Chapitre 3 - Fatigue Risk Management System

Five-Level Fatigue Hazard Control Model
Five-Level Fatigue Hazard Control Model

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3.1 Preface (Mandatory)

An effective fatigue risk management plan should take a systems approach to minimizing fatigue-related incidents. The FRMS section of this policy tool is based on the five-level error trajectory (see Developing and Implementing a Fatigue Risk Management System (TP 14575E) for more detailed discussion). At Level 1, organizations must provide sufficient sleep opportunity to all employees. This can be achieved either through prescriptive hours of service rules or computerbased fatigue modelling (see Section 3.3). At Level 2, organizations should encourage employees so that, when provided with sufficient sleep opportunity, they strive to obtain sufficient sleep. This can be done in a number of different ways, as outlined in Section 3.4. At Level 3, organizations should monitor the frequency that employees exhibit fatigue-related symptoms, regardless of sleep opportunity and actual sleep obtained. If employees appear to be exhibiting fatigue-related symptoms, their ability to perform high-risk tasks should be examined by an appropriate manager. This process is outlined in more detail in Section 3.5. Level 4 deals with fatigue proofing situations that may involve higher levels of fatigue-related risk, such as emergency overtime or extreme weather. See Section 3.6. The final level in the error trajectory is concerned with reporting errors and incidents that may be fatigue-related. Details of this process are given in Section 3.7.

The information presented under each of the following sections is not intended as a prescriptive formula for the development of a Fatigue Risk Management System. You should use this material to tailor an FRMS to suit the size and nature of your operation. This will ensure a level of owner ship by both management and operational personnel.

As with any Safety Management System, commitment from management and clear consultation with employees ensures a positive safety culture that is the foundation for success.

An FRMS should be part of your wider SMS as an integrated set of work practices and procedures for monitoring and improving the safety of all aspects of your organization. It recognizes the potential for fatigue-related errors and establishes robust defences to minimize the likelihood of incidents or accidents.

As with all safety management systems, fatigue risk management involves goal setting, planning, documentation, and measuring performance against goals. An FRMS should be a comprehensive, integrated tool for managing fatigue in operational settings.

This section should include general information about the FRMS and provide a framework for the remainder of the manual. It should say why the FRMS has been implemented and list the basic components that it covers.

Points to Consider

  • What is the basic structure of the FRMS?

Sample Text

Section 3.1    Preface (Mandatory)

The FRMS incorporates fatigue hazard control mechanisms to ensure:

  • sufficient sleep opportunity is given to employees (see Section 3.3)
  • actual sleep obtained is verified (see Section 3.4)
  • procedures for monitoring and dealing with fatigue-related symptoms (see Section 3.5)
  • fatigue-proofing strategies are implemented to reduce fatigue-related risk (see Section 3.6)
  • fatigue-related accident/incident investigation procedures are in place (see Section 3.7)

The FRMS is based on the five-level error trajectory shown below.

Five-Level Fatigue Hazard Control Model
Five-Level Fatigue Hazard Control Model

3.2 FRMS Policy

3.2.1 Senior Management Commitment to Managing Fatigue (Mandatory)

Every organization is unique in terms of the size of its operation, layout of its facilities, frequency of aircraft movements, and maintenance and flight operations. The FRMS you develop needs to be tailored to meet the needs of your specific operation.

This section must contain a clear commitment to the FRMS from the organization’s senior management. This is an overall statement about the management of fatigue hazard (see Developing and Implementing a Fatigue Risk Management System (TP 14575E) for an example of such a mission statement). The statement outlines the corporate philosophy of fatigue risk management and clearly identifies the person(s) responsible for oversight of the FRMS within the company. FRMS policies and procedures must be communicated to all employees with a clear endorsement by senior management.

Your policy statement should clearly state:

  • commitment of senior management to the FRMS
  • responsibilities and accountability of the accountable executive, managers, committees, and employees
  • how the organization will achieve its safety objectives
  • resources allocated
  • fatigue-related safety outcomes expected of managers, employees, and contractors

You should also include a statement explaining how the FRMS interacts with your SMS.

Points to Consider

  • Has senior management given support and commitment to FRMS implementation?
  • What is the overall purpose of the FRMS?
  • What resources are allocated for the FRMS?

Sample Text

Section 3.2.1    Senior Management Commitment to Managing Fatigue (Mandatory)

  1. [Insert Company Name]’s Fatigue Risk Management System policy represents the strongest commitment at the highest level — signed by the accountable executive.

    [insert Company Name] is committed to protecting all employees, contractors, service providers, clients, visitors, and the general public from fatigue-related risk. There will be no compromise in an employee’s well-being in anything we do. Implementing measures to minimize fatigue-related risk and create a safe, healthy, and injury-free environment is a leadership responsibility. Continuing support of this effort is the responsibility of everyone.
  2. The purpose of the FRMS is to reduce, as far as practicably reasonable, workplace fatigue and its risks, to ensure a safe and error-free work environment for employees, contractors, and clients. The objectives of this policy are to ensure:
    • Employees are fit for work
    • The company enjoys a safe working environment by minimizing hazards associated with fatigue
    • The fatigue hazards associated with long work hours and shift work are minimized
    • Employees have access to assistance through a range of preventative initiatives, including training
    • Informed decisions are made about work design
    • On-going risk assessment and hazard monitoring takes place
    • Employees unfit for duty as a result of fatigue will be dealt with consistently and fairly in accordance with this policy

Resources for maintenance, development and implementation, updating and reporting of fatigue in the workplace in relation to the FRMS policy and personnel responsible for it will be through the Human Resources Department (or similar).

3.2.2 Fatigue-related Safety Objectives (Mandatory)

Fatigue-related safety objectives form the basis for measuring the success of the FRMS components. Safety objectives need to be specific, measurable, realistic, and have the backing of those who have to deliver them. Both short- and long-term objectives should be set and prioritized, and balanced with business requirements.

Fatigue risk management objectives are outcome-based to meet the organization’s safety policies. They should be transparent to employees and customers and clearly outline expectations and intent to ensure a safe work environment for everyone.

It is essential that employees know how these objectives affect their job functions and roles. Simply informing employees that they need to manage fatigue-related risk is not sufficient. They should be given operational roles or responsibilities that ensure fatigue-related risk is managed appropriately.

Points to Consider

  • What does the organization aim to achieve with FRMS implementation? (This may extend beyond the reduction of fatigue-related risk to aspects such as increased employee morale or increased performance capacity)
  • How does the organization plan to achieve that?

Sample Text

Section 3.2.2    Fatigue-related Safety Objectives (Mandatory)

All levels of management are committed to managing the risk of workplace fatigue. This company has clear employee safety standards with clear accountability, as outlined in Section 2.3.

We involve everyone in the process, as described in Section 3.2.

We provide the necessary training to build and maintain meaningful fatigue-risk management safety leadership skills, as stated in Section 4.

3.2.3 Communication and Consultation (Mandatory)

As with the wider SMS, information on FRMS policies, objectives, and responsibilities must be clearly communicated to staff, consultants, customers, and other appropriate individuals.

Where possible, the communication process should be recorded and filed for future reference by management and/or a Transport Canada audit team. Methods of communication could include memos, e-mail, or posters. Employees may be invited to submit agenda items to the FRMS Committee.

Whatever the method, communication needs to be clear and unambiguous, specific, and easily transferred and recorded by some means. An important step in this communication process is feedback.

Feedback can be formal and informal. Formal communication may take the form of minutes from the FRMS committee meetings or newsletters. Informal communication may be verbal. For example, a supervisor may update employees on the outcome of a fatigue-related issue during a lunch break.

In this section, you need to describe how you will distribute FRMS-related information, throughout the organization. What method will you use? How is the information to be distributed? Who is responsible? What is the time frame?

You also need to describe the methods of communication between the person/committee responsible for the FRMS and senior management. For example, regular, scheduled meetings with a set agenda or e-mail updates following each FRMS committee meeting.

This section should also detail the level of consultation with levels of management and employees during the FRMS design and review process. All employees should have the opportunity to participate in the FRMS design and review. There are many ways of achieving this. For example, focus naires, or employees may be asked to e-mail feedback.

Finally, you need to describe how you will distribute non-critical information related to fatigue. This might include educational information related to personal fatiguerisk management strategies. Examples might include memos, website, company newsletter, and safety notice boards.

Points to Consider

  • How will information related to the FRMS be distributed and recorded?
  • Who needs to receive FRMS related information?
  • What level of consultation will be conducted among employees during the FRMS design and review process?
  • Who will be involved in the FRMS consultation process?
  • How will the FRMS consultation process be conducted?

Sample Text

Section 3.2.3    Communication and Consultation (Mandatory)

  1. The person/committee responsible for the FRMS will distribute information about the FRMS and informing all employees of their individual responsibilities. The preferred method of delivery for critical safety-related information at this organization is through safety meetings, followed up by e-mailed meeting minutes.

    All employees will be consulted during the FRMS design and review processes. Employees will be given a training session on fatigue-risk management and FRMS components (see Section 4). Each training session will be followed by a focus group, during which employees will be able to provide feedback on the framework of the FRMS. Feedback provided through the focus groups will form the basis of any changes to the FRMS during the review process.
  2. Whenever there is an urgent need to distribute fatigue-related safety information or to take safety-related action, employees will be notified directly by their supervisors. An update on FRMS activities will be published and e-mailed to all staff twice a year.

    Employees will be consulted during any review of the FRMS. Employees will receive a copy of the FRMS along with a questionnaire to be returned to the person responsible for the FRMS. Feedback provided through the questionnaire will be considered during the annual FRMS review process.

3.3 Hours of Service and Scheduling (Mandatory)

The degree of work-related fatigue associated with a given task on a given schedule is linked to the degree a schedule precludes sleep of sufficient quality and duration to ensure employees are fit for work. A schedule produces higher levels of work-related fatigue if it requires an employee to work more often at times when one is socially and biologically predisposed to sleeping.

It is important that schedules provide employees with sufficient sleep opportunity to ensure they are fit for work. The factors that affect sleep opportunity are the length and timing of shifts, time away from work, long blocks of shifts, and biological limits on recovery.

There are a number of ways to ensure employees have been provided with sufficient sleep opportunity within a schedule:

  • operate within federal or provincial hours-of-work rules
  • use a computer-based fatigue modelling package
  • use a fatigue likelihood scoring matrix

Biomathematical modelling

Many models predict fatigue based on planned or actual hours of work. They consider a number of factors including the timing and duration of all shifts in the previous days (with more weight given to more recent shifts). Most models also allow comparison of various schedules and the fatigue “scores” that each may produce in an employee population.

Using a “fatigue score” as an index of average sleep opportunity, organizations can determine whether sleep opportunity is adequate by comparing the estimated fatigue score to a threshold value established by the organization in advance. Schedules that produce a score over this threshold value may be considered to provide inadequate sleep opportunity. Any organization that chooses to use a biomathematical model should set threshold values for fatigue scores based on a risk assessment of the tasks found in the workplace. The risk assessment process may identify different task categories that require different threshold values based on their susceptibility to fatigue impairment. These threshold values are used to establish compliance tables for the schedules of various workgroups. To keep compliance tables convenient to manage, task categorization should be broad and based on criticality and susceptibility to fatigue risks.

The most effective way to use biomathematical models for scheduling is to set risk-based limits and restrict how much of the schedule exceeds them. Using this approach, the company defines acceptable, questionable, and unacceptable zones. Fatigue (sleep opportunity) scores (based on a task-defined risk assessment) are assigned to the acceptable/questionable and questionable/unacceptable thresholds.

Organizations should not intentionally schedule work with scores in the unacceptable zone and 95% of actual work hours must fall within the acceptable zone. A small percentage of total hours are permitted for scheduled work in the questionable zone. Circumstances may sometimes dictate that actual hours worked fall in the unacceptable zone. All work in zones other than acceptable must be investigated and appropriate corrective action taken. An example of a compliance table that shows threshold values, percentages of planned and actual hours of work, and corrective actions is shown below.

Create a compliance table or a list of threshold values as needed for each task category defined in the risk assessment process. The FRMS manual could also contain a list of corrective actions to be taken when necessary.

Example of a compliance table used with biomathematical modelling

of work
of work
Corrective Action
Acceptable < X 97.5% 95% None unless one or more controls
indicate levels are wrong
Questionable [X-Y] 2.5% 3.75% Correct if there is moderate chance
of recurrence
Unacceptable > Y 0% 1.25% Act immediately
Rest until fit for duty
Report to regulator

Fatigue Likelihood Scoring Matrix for Work Schedules

An alternative assessment tool to the biomathematical model is a fatigue likelihood scoring matrix. There are five key elements that make up this matrix:

  1. The total number of hours worked in a seven-day period. As total hours worked increases, sleep opportunity decreases.

  2. The maximum length of an individual shift. As the length of a given shift increases, the subsequent sleep opportunity decreases.

  3. The minimum length of a short break. A short break is defined as a single sleep opportunity between work periods. It is typically a period shorter than 32 hours. As the break between shifts decreases, so does the sleep opportunity.

  4. The total number of hours worked between 9 p.m. and 9 a.m. in a seven-day period. This element captures late finishes, early starts, and night work. All of these will reduce the night sleep opportunity and result in a significant reduction in total sleep opportunity.

  5. The frequency of long breaks. A long break is defined as a period of two night sleeps with a non-working day in between. Long breaks typically provide a significant opportunity to recover from sleep loss accumulated over a sequence of work periods.

A schedule can then be scored on each of the five elements using the following table.

Fatigue Likelihood Scoring Matrix for Work Schedules

Score 0 1 2 4 8
a) Total hours
per 7 days
< 36 hours 36.1 – 43.9 44 – 47.9 48 – 54.9 55+
b) Maximum shift duration < 8 hours 8.1 – 9.9 10 – 11.9 12 – 13.9 > 14
c) Minimum short break duration > 16 hours 15.9 – 13 12.9 – 10 9.9 – 8 < 8
d) Maximum night work per 7 days 0 hours 0.1 – 8 8.1 – 16 16.1 – 24 > 24
e) Long break frequency > 1 in
7 days
< 1 in
7 days
< 1 in
14 days
< 1 in
21 days
< 1 in
28 days

The points for each element can then be added to provide a score between 0 and 40 that indicates the degree of sleep opportunity afforded by the schedule. Schedules with a lower score provide greater sleep opportunity (and are less likely to be associated with work-related fatigue) than those with a higher score. Organizations must define what they deem to be acceptable or unacceptable. The cut-off point for an acceptable schedule is determined by the specific characteristics of the organization. For example, an organization could choose to assign a lower cut-off score for highly complex or safety-critical work, or a high physical stress work environment (e.g. high humidity), than less complex or safety-critical work in an air-conditioned environment.

Organizations should consider consulting with employees, the regulator, researchers, and others in the industry to establish some initial standards for how sleep opportunity can be assessed using each of these approaches and appropriate threshold values for adequate sleep opportunity for various categories of employees in the Canadian aviation industry.

Points to Consider

  • How likely are employees to be fatigued due to lack of sleep opportunity in their work schedule (night work, early morning starts, extended shifts, overtime, long blocks of shifts, amount of time away from work, commute time, etc.)?
  • How will the work schedules be assessed for fatigue-related risk?
  • What is the level of fatigue-related risk associated with work tasks within the organization?
  • What benchmark is the organization using to define fatigue-related risk as acceptable, questionable, or unacceptable?
  • What procedures are in place for when work schedules fall within the questionable zone?

Sample Text

Section 3.3    Hours of Service and Scheduling (Mandatory)

Work schedules will be assessed for adequate sleep opportunity and considered appropriate according to the following compliance table. Planned work hours will be assessed in advance, whereas actual work hours shall be assessed retrospectively.

Through the planning phase, work schedules will be assessed using a Fatigue Audit InterDyne (FAID) software assessment tool to determine whether employees have been provided with adequate average sleep opportunity. Fatigue-related risk will be managed using a risk control process. Management will undertake a fatigue-related risk assessment for specific work groups and tasks. These will be assigned a nominal upper limit consistent with a safe system of work.

The compliance table below for [insert task category designator] shows the FAID threshold values for providing sufficient sleep opportunity. The upper threshold sets the limit for an acceptable degree of sleep opportunity provided by a work schedule for the designated group of employees. FAID scores above [insert upper threshold value] are considered to be in the unacceptable zone. The lower threshold is set at [insert lower threshold value — for FAID this is typically 10-20 points below upper threshold]. FAID scores falling between the upper and lower thresholds are in the questionable zone, and scores below the lower threshold are in the acceptable zone. Compliance is determined by calculating the percentage of total hours worked above the two designated thresholds.

Compliance table for [insert task category designator]

of work
of work
Corrective Action
Acceptable < X No less than 97.5% of scheduled hours No less than 95% of hours worked None unless evidence of Level 2 hazards or higher are present
Questionable [X-Y] No greater than 2.5% of scheduled hours No greater than 3.75% of hours worked Where there is reasonable likelihood of recurrence (more than twice in a row), investigate and undertake corrective action before next audit
Unacceptable > Y 0% of scheduled hours No greater than 1.25% of hours worked Investigate and undertake immediate corrective action

Work schedules will be analysed monthly during normal operations and weekly during contingency situations. [Insert company name] will not intentionally plan work beyond the upper threshold value (i.e., operate in the unacceptable zone) and will be required to achieve compliance for 95% of actual hours of work (i.e., in the acceptable zone). Percentages in the remaining boxes shall be limited to the percentages specified in the compliance table. Thus, up to 1.25% of total hours may occur in the unacceptable zone due to unforeseeable circumstances, up to 2.5% of hours may be planned occasionally in the questionable zone and up to 3.75% permitted in practice. 97.5% of hours shall be planned within the acceptable zone.

3.4 Verification of Actual Sleep (Mandatory)

The primary physiological determinants of fatigue for a given employee carrying out a given task are the timing and duration of prior sleep and time awake. These factors are the most appropriate criteria for judging whether an employee is likely to be fit for work. The hours of service and scheduling rules outlined in the preceding section are effective in predicting how much sleep an employee is likely to obtain in a given break from work. Level 2 control, however, aims to ensure that individual employees actually obtained sufficient sleep.

The focus of this level of control is setting minimum and maximum thresholds for sleep and time awake for employees to ensure that they are fit for duty. These minimum and maximum thresholds may vary for a specific task category or work group, according to the risk profile, but they can provide a simple, practical, and easily measurable yardstick to determine whether an employee has obtained sufficient sleep and is, by inference, fit for work.

These thresholds are equivalent to the simple formula used by people to determine whether they are alcohol impaired. For example, in counting number of drinks they have had over a period of time. While counting sleep and time awake is not a perfect indicator of the level of fatigue for all individuals on all occasions, it can provide employees with a simple measure for determining the relative likelihood that they are fatigued.

Calculating an Individual Fatigue Likelihood Score (IFLS)

Most evidence suggests that to maintain optimum performance, health, and wellbeing, individuals should get between seven and nine hours sleep per 24-hour period.

Many studies have investigated how decreasing levels of sleep and increasing time awake affects performance (see references in Section 7). In general, research has found that performance begins to become impaired after less than five hours sleep over a 24-hour period. Performance also becomes impaired if sleep consistently falls below six hours per night on an ongoing basis (over the period of a week).

A measure of fitness-for-duty related to fatigue can be calculated using the following table.

As prior sleep decreases and time awake increases, the likelihood of fatigue-related symptoms, errors, and incidents also increases. In general, X should be greater than 5, Y should be greater than 12 and Z should be less than Y. Each of the factors (X, Y, and Z) are added to provide an overall score of individual fatigue likelihood. Employees who obtain an elevated score should inform the appropriate supervisor or manager, and appropriate action should be taken. It is useful to establish a decision tree for employees and managers that provides clear information about appropriate action at various levels of fatigue. The table below shows an example.

How to calculate the Individual Fatigue Likelihood Score

Prior sleep/wake factor Threshold value Scoring*
X (sleep in prior 24 hours) 5 hours Add 4 points for every hour below threshold
Y (sleep in prior 48 hours) 12 hours Add 2 points for each hour below threshold
Z (time awake since last sleep) Y Add 1 point for each hour of wakefulness greater than Y

* Partial hours should be pro-rated or scored proportionally. For example, if the scoring calls for 4 points for every hour below the threshold, give 2 points for a half-hour, or 1 point for 15 minutes.

Decision tree based on Individual Fatigue Likelihood Score

Individual Fatigue Score Risk Level Approved Controls
Zero Acceptable No additional controls necessary except in the presence of higher level indicators of fatigue (i.e., symptoms, errors, or incidents).
[Zero-A] Minor Report fatigue to local supervisor. Implement approved individual controls including, but not limited to: symptom monitoring, strategic use of caffeine, task rotation, increased personal and co-worker monitoring.
[A-B] Moderate Report fatigue to local manager. Implement additional approved individual controls, including but not limited to: task reallocation, napping, increased level of supervisory monitoring.
> B Significant File formal fatigue report. Do not engage in safety-critical tasks. Do not recommence work until sufficiently rested as per prior sleep/wake rules.

Scores that constitute A and B should be worked out on an industry, sector, or organizational basis. They should be based on overall job risk and consultation with employees.

Potential Applications of the Individual Fatigue Likelihood Score (IFLS)

One way to use the IFLS as a Level 2 control is to apply the minimum sleep and maximum time awake rules as a simple self-assessment tool embedded in the training program. Employees would determine their own risk of fatigue and be required to manage their own fatigue with countermeasures such as sleep planning, strategic napping, caffeine, breaks, task rotation, etc.

Or employees might be required to report actual sleep obtained on a daily basis to the employer and to engage in clearly defined and documented risk mitigation strategies. In this case, the organization should design specific decision trees for designated tasks or work groups indicating what should be done at specified IFLSs. Levels of risk mitigation should increase with higher IFLSs. Examples of fatigue control measures for the various levels of risk are presented below.

Minor increase in risk: At this level, individual fatigue controls implemented by the employee are most common. Employees should report the level of fatigue-related risk to the appropriate supervisor according to the organizational reporting structure. The use of symptom checklists prior to starting work would be appropriate as would an increased level of supervision by the employee and/or by co-workers. Appropriate use of caffeine may be recommended, particularly during hours when an employee would typically be asleep. It would also be reasonable for the employee and/or co-workers to restructure work tasks and/or breaks to minimize any additional risk.

Moderate increase in risk: No employee should begin work with an IFLS in this range without completing a symptom checklist and indicating in writing that they consider themselves fit to work. Supervisors should discuss the work assignment with the employee and ensure that the number of safety-critical tasks are minimized and that all reasonable efforts are made to reallocate the workload safely. Employees with an IFLS in this range would receive priority for napping, where possible. The use of caffeine or other strategies to stay awake (bright lights, exercise, cool air, noise or upbeat music, etc.) would be common.

Significant increase in risk: An employee with an IFLS in this range would typically be considered unfit for work. This level of impairment is broadly comparable to drug or alcohol intoxication. It is unlikely that an employee would be permitted to undertake any safety-critical task and would probably not be allowed to drive to or from the workplace. Activities should not require employees to be responsible for the safety of themselves or others and should be limited to simple tasks in a relatively hazard-free environment. Before returning to work, all employees should be given adequate opportunity to obtain sufficient sleep. In general, employees should not be required to return until their fatigue likelihood score is zero.

When an employee notifies a supervisor or line manager of an elevated fatigue score, the reasons for the score need not to be discussed unless the employee reports such a score more than three times in 90 days. Discussions about the cause of multiple reports should typically involve the employee assistance program in the first instance (where applicable) and can subsequently involve line managers and supervisors where appropriate.

Using the Individual Fatigue Likelihood Score (IFLS) to Improve Work Scheduling Practices

Level 2 controls are designed to ensure adequate sleep at the individual level. They use relatively objective measures that are intuitively meaningful, observable, and easily recorded at the individual and group levels.

If an organization emphasizes Level 2 controls and they are reliably reported and documented, they can also be used to collect valuable data on fatigue in the organization. The data could be aggregated across an entire organization or even industry to provide the basis of a statistically sound approach to evaluating the amount of sleep and time awake provided by a schedule and form the basis for evaluating the effectiveness of scheduling factors set out in Section 3.3.

Points to Consider

  • What is the minimum amount of sleep required to be considered fit for work:
    • on a one-time basis?
    • on a continual basis?
    • for high-risk work?
    • for low-risk work?
  • What are the measures or procedures to follow when an employee has not obtained sufficient sleep?
  • What should be done when this happens repeatedly?
  • What policies or procedures are in place for contractors working on site?

Sample Text

Section 3.4    Verification of Actual Sleep (Mandatory)

Prior to starting work, employees who have undergone fatigue management awareness training will be required to assess their fitness-for-work risk by calculating their individual fatigue likelihood score for the previous 48 hours. The result helps employees determine the likelihood of fatigue-related impairment and the degree of safety associated with scheduled work activities.

An individual fatigue likelihood score (IFLS) can be calculated using the following table.

How to calculate the Individual Fatigue Likelihood Score

Prior sleep/wake factor Threshold value Scoring*
X (sleep in prior 24 hours) 5 hours Add 4 points for every hour below threshold
Y (sleep in prior 48 hours) 12 hours Add 2 points for each hour below threshold
Z (time awake since last sleep) Y Add 1 point for each hour of wakefulness greater than Y

* Partial hours should be pro-rated or scored proportionally. For example, if the scoring calls for 4 points for every hour below the threshold, give 2 points for a half-hour, or 1 point for 15 minutes.

If the assessment finds an elevated level of fatigue-related risk, the employee should inform the appropriate line manager or supervisor as soon as practical. Together, the employee and manager should discuss and implement appropriate controls. Employees who report a non-zero score more than 3 times in 90 days will be referred to the employee assistance program to discuss potential reasons and solutions for the lack of sleep.

The following decision tree indicates proper course of action to follow, based on IFLS scores.

Decision tree based on Individual Fatigue Likelihood Score

Individual Fatigue Score Risk Level Approved Controls
Zero Acceptable No additional controls necessary except in the presence of higher level indicators of fatigue (i.e. symptoms, errors, or incidents).
1-4 Minor Inform line supervisor and document in daily logbook. Self-monitor for fatigue-related symptoms, and apply individual controls such as strategic use of caffeine, task rotation, working in pairs, additional rest breaks.
5-8 Moderate Inform local manager and document in a fatigue report. Implement additional fatigue controls such as task reallocation, napping, and increased level of peer and supervisory monitoring.
9+ Significant Call manager before driving to work. Document in a fatigue report on next work shift. Do not engage in safety-critical tasks (including driving to work), and do not return to work until sufficiently rested as per sleep/time awake rules.

Each employee will be provided with a pocket card for easy reference.


Individual Fatigue Likelihood

Step 1. Sleep in prior 24 hours

Sleep   <2h   3h   4h   5+h 
Points 12 8 4 0

Step 2. Sleep in prior 48 hours

Sleep   <8h   9h   10h   11h   12+h 
Points 8 6 4 2 0

Step 3. Hours awake since last sleep
Add one point per hour awake greater
than sleep in step 2.


Individual Fatigue Likelihood

Step 4. Sleep in prior 24 hours

Add all points together to determine
your score

Score   Control Level 
1-4 Self-monitoring
5-8 Supervisor monitoring
9+ Don’t start shift until fit
for work

Refer to FRMS policy for detailed
explanation of controls

Untrained Employee/Contractor Assessment

Employees and contractors who have not taken fatigue management training are asked to confirm that they have had a minimum of six hours sleep in the 24 hours prior to starting work.

Where employees have not had six hours of sleep, they are required to report this to an appropriate individual. A risk assessment must be conducted to determine the appropriate action. As a general rule, obtaining only five to six hours of sleep should be considered a minor hazard, obtaining four to five should be considered a moderate hazard, and obtaining less than four should be considered a significant hazard.

In general, managers and supervisors should use controls similar to those outlined in the decision tree. This may include but is not limited to: task rotation, napping, workload reallocation, sending the employee home, provision of transport off site, and/or requiring the employee get adequate sleep prior to returning to work.

3.5 Fatigue-related Symptoms (Mandatory)

Level 3 controls are concerned with reducing the likelihood that employees exhibit fatigue-related symptoms – and reducing the consequences. There are many reasons that an employee may appear to be or act fatigued. If the FRMS is operating effectively, the main cause – insufficient sleep – should be screened out by Level 1 or 2 controls.

The type of work performed may be particularly physically or mentally demanding, which can exacerbate fatigue and lead to fatigue-related symptoms. External factors such as weather can also affect fatigue. These factors should all be considered in the risk assessment of work tasks so that scheduling parameters can be set for different work groups or work tasks where warranted. The appearance of fatigue-related symptoms during certain work periods or tasks can be an indication that risk profiles need to be reassessed.

There may be situations where fatigue-related symptoms are not directly linked to work tasks or environmental conditions, and where the employee has been provided sufficient opportunity and actually obtained sufficient sleep. Nonwork factors are likely the cause. For example, the employee may be experiencing personal stress (e.g., sickness, newborn baby, financial issues, divorce) that is disturbing sleep.

Employees who say they get enough sleep and cannot explain their fatigue-related symptoms should undergo screening for a sleep disorder. Some of the more common sleep disorders are discussed in Developing and Implementing a Fatigue Risk Management System (TP 14575E). Employee Suspected of having a sleep disorder should be referred to a doctor or sleep specialist as soon as possible, particularly if they are performing high-risk tasks.

Level 3 controls – observing and reporting fatigue-related symptoms – are important in an effective FRMS to determine whether:

  • minimum sleep requirements are appropriate
  • task-scheduling processes are appropriate
  • non-work activities are affecting the risk of workplace fatigue
  • employees have a sleep disorder

The following table lists typical symptoms of fatigue. If employees have experienced more than three of the specified symptoms in a 15-minute-period, they are likely to be fatigued and should be considered at an elevated level of fatigue-related risk.

Symptoms of fatigue

Physical Symptoms Mental Symptoms Emotional Symptoms
  • Yawning
  • Heavy eyelids
  • Eye-rubbing
  • Head drooping
  • Inappropriate or unintentional dozing
  • Difficulty concentrating on the current work task
  • Lapses in attention
  • Difficulty remembering what you are meant to be doing
  • Failure to communicate important information to a colleague
  • Failure to anticipate events or actions
  • Unintentionally doing the wrong thing (errors of commission)
  • Unintentionally failing to do the right thing (errors of omission)
  • More quiet or withdrawn than normal
  • Lethargic or lacking in energy
  • Lacking in motivation to do the task well
  • Irritable or bad tempered with colleagues, family, or friends

In addition to general symptoms of fatigue, most employees are also aware of task-specific indicators of fatigue. These should be identified during the task assessment and included in the table of reportable symptoms. Actions to be taken when fatigue-related symptoms are observed and reported should be determined in a similar fashion to Level 1 and 2 controls.

When employees notice symptoms of fatigue in a co-worker, they should point it out to the co-worker. If the situation arises again, employees should encourage the coworker to report the fatigue and take the precautions outlined in the FRMS manual.

Employees repeatedly exhibiting fatigue-related symptoms should be encouraged to consult medical specialist to determine whether they suffer from a sleep disorder. This is particularly important for employees with a body mass index greater than 30 kg/m2 and a neck size greater than 16 inches (40 cm) since they are at a greater risk for sleep apnea.

Some organizations are exploring performance testing technologies that could theoretically provide a more objective indication of fatigue-related impairment. Some of the main technologies currently available include the Occupational Safety Performance Assessment Test (OSPAT), psychomotor vigilance tests (PVT), Digit-Symbol Substitution Tests (DSST), pupillometry and blink tests. While some of these technologies are promising, they have not yet been shown to be sufficiently scientifically reliable to serve as a sole means to detect fatigue-related impairment.

Using Symptom Data to Assess Level 1 and 2 Controls

Documenting Level 3 controls can help double-check that Level 1 and 2 controls are appropriate. For example, if there is a high incidence of fatigue-related symptoms, and employees say they are complying with the organization’s minimum sleep requirements, the scoring system for sufficient sleep may need to be reviewed.

Fatigue-related symptoms can also flag employees who breach their responsibility of obtaining appropriate sleep in the time provided. For example, it is unlikely that employees who choose to engage in social activities rather than sleep will report their inadequate sleep to management. If employees regularly demonstrate fatigue-related symptoms, they may need to be reminded of their responsibility under the FRMS to arrive at work fit for duty.

Level 3 controls can also flag employees who experience disturbed sleep quality or quantity beyond their or their employer’s control, and who may be impaired by fatigue.

Points to Consider

  • What are the main fatigue-related symptoms experienced by employees in the work environment?
  • What symptoms are particularly indicative of being unfit for duty due to fatigue?
  • How should fatigue-related symptoms be reported/used within the overall FRMS?

Sample Text

Section 3.5    Fatigue-related Symptoms (Mandatory)

[Insert company name] recognizes that a result of zero on the IFLS is not a guarantee that an employee is fit for work with respect to fatigue. Personal (stress, medical condition, etc.) and work-related factors (weather, time pressures, etc.) may contribute to the level of fatigue. Employees and supervisors are expected to be proactive in observing and acting on fatigue-related symptoms in one another. Typical symptoms of fatigue are listed in the table below. If a symptom of fatigue is observed in another person, it should be brought to that person’s attention. As a guideline, if an employee experiences more than three of the specified symptoms in a 15-minute period they are likely to be fatigued and should be considered to be at an elevated level of fatigue-related risk. Appropriate fatigue control measures need to be applied. Employees that repeatedly exhibit fatigue-related symptoms over a number of shifts will be referred to the employee assistance program, screened for sleep disorders, and may be provided further consultation with a doctor and/or sleep specialist. Reporting protocols are outlined later in this document.

Symptoms of fatigue

Physical Symptoms Mental Symptoms Emotional Symptoms
  • Yawning
  • Heavy eyelids
  • Eye-rubbing
  • Head drooping
  • Inappropriate or unintentional dozing
  • Difficulty concentrating on the current work task
  • Lapses in attention
  • Difficulty remembering what you are meant to be doing
  • Failure to communicate important information to a colleague
  • Failure to anticipate events or actions
  • Unintentionally doing the wrong thing (errors of commission)
  • Unintentionally failing to do the right thing (errors of omission)
  • More quiet or withdrawn than normal
  • Lethargic or lacking in energy
  • Lacking in motivation to do the task well
  • Irritable or bad tempered with colleagues, family, or friends

3.6 Fatigue-Proofing Strategies (Recommended)

The main benefit of an FRMS is to provide organizations and employees with an increased level of safety management. The scheduling guidelines set out in Section 3.3 should be used for the majority of the company’s operations. However, there will be occasions when operational demands require extended hours of work. This may result in employees working through higher levels of fatigue than normal.

In these situations, there are a number of strategies that can be used to reduce the consequences of increased fatigue. For example, management may rely more heavily on Level 2 and 3 controls. This can help to determine which employees are most appropriate to complete the additional duties. To prevent fatigue-related errors, management should use Level 4 strategies, such as:

  • napping
  • supervisor and co-worker monitoring
  • double-check systems
  • task rotation and reallocation
  • additional breaks and strategic use of caffeine

The organization should provide guidelines on how each of these can be used.

Napping: As a general rule, those with the highest risk should have the highest priority for napping. In general, the longer the nap the greater the recovery value. Naps should last at least 20 minutes and no more than two hours to be of maximum benefit. Shorter naps do not produce appreciable or lasting improvements in alertness. Sleeping more than two hours brings little additional benefit, particularly when that time could be used to provide another employee with a napping opportunity. Where controlled napping is allowed, the company should detail the circumstances under which it is permitted.

It is important to keep in mind that longer naps are associated with a longer period of sleepiness immediately following waking. This effect is known as sleep inertia. Employees should be given sufficient time to overcome the effects of sleep inertia before returning to work. Typically, this is at least 10 minutes during the day, and up to 20 minutes in the early hours of the morning.

Monitoring and double-check systems: Where an employee is at an elevated risk of fatigue-related error, increased monitoring by peers or supervisors for fatigue-related symptoms and/or impaired task performance can be an effective strategy. However, this can be a sensitive issue and it is important that the criteria for increased monitoring are clear in advance to minimize misunderstanding.

Increased monitoring can be achieved in a number of ways. It can be as simple and informal as more frequent or regular conversations with the employee over the course of the shift. Or it can involve more formal policies or procedures that call for additional, verified supervisory checks on safety-critical work by the fatigued impaired employee, co-workers, or a supervisor/line manager.

Task rotation and reallocation: Monotonous tasks with little variety are particularly susceptible to the effects of fatigue. In many cases, the workload can be made more engaging by varying the tasks during a shift. It is important to understand that the benefits of task rotation do not increase linearly. In general, the number of different tasks undertaken in a given shift should not exceed three or four, or the risk of error due to unfamiliarity with the job at hand may rise. Where task rotation forms part of the control system for fatigue-related risk, the number and types of tasks allocated should be determined in consultation with employees.

When an employee shows signs of fatigue, or when a self-assessment tool indicates impairment from fatigue is likely, the employer should make sure that the employee is not given certain tasks that may be high-risk to the employee, colleagues, the work flow, and/or the general public. Acceptable activities might include simple procedural tasks, word or data processing, quality checks, and basic communication. This reduces the risk of an incident, but does not mitigate the employee’s fatigue.

Additional breaks and strategic use of caffeine: When operational requirements call for longer hours of work, additional breaks should be provided to employees when fatigue may impair their performance. A break of 10 to 20 minutes may permit improvements in performance on a short-term basis. Employees assigned to tasks that require sustained attention over prolonged periods of time should take a break at least every two hours. Research shows that performance starts deteriorating after two hours on high-demand tasks. The breaks should be used to engage in strategies to improve alertness, e.g., walk outside to get some fresh air, exercise, have a coffee, etc.

Caffeine can provide a short-term improvement in alertness when it is used strategically. A typical dose of caffeine (75 to 150 mg) will provide an increase in alertness approximately 20 minutes after ingestion. The stimulating effects will vary in intensity and duration (up to four hours) depending on how often and how much caffeine the body is used to. However, the body can develop a tolerance, meaning the more caffeine the body gets on a daily basis, the less noticeable are the stimulating effects.

The best way to think about caffeine is that it has the capacity to “shift” fatigue and alertness to more appropriate times. However, there are significant disadvantages to prolonged regular caffeine use. Individuals differ enormously in their sensitivity to both the positive and negative effects of caffeine.

Points to Consider

  • What strategies will be employed to avoid fatigue-related errors when employees need to work through high levels of fatigue?

Sample Text

Section 3.6    Fatigue-Proofing Strategies (Recommended)

There may be occasions when operational demands require employees to work longer hours than normal. A number of control factors will be put in place. First, employees required to work additional work hours will be asked whether they have obtained six hours sleep in the last 24 hours. If they have not, fitness for duty will be considered using the protocol outlined in Section 3.4. In addition, employees will be required to complete a symptom checklist (see Section 3.5) every two hours. If an employee reports more than three symptoms, their fitness for duty should be examined by a supervisor. If at any stage an employee feels unfit for work, they will be relieved of duty and sent home or given an opportunity to rest.

A number of controls or strategies can be used to minimize the likelihood of errors when employees experience low or moderate levels of fatigue. These include:

  • napping
  • supervisor and co-worker monitoring
  • task rotation and reallocation
  • additional breaks and strategic use of caffeine

Where appropriate, employees may be allowed to take a nap or controlled rest. [Insert company name] has provided a limited number of short-term sleeping facilities for employees during working hours.

Highest priority for napping will be given to those with the highest fatigue-related risk. Naps shall be at least 20 minutes and no more than 2 hours, depending on operational constraints and fatigue risk involved. Before returning to work after a nap, employees will be given sufficient time to overcome the effects of sleep inertia. Typically, this is at least 10 minutes during the day, and up to 20 minutes in the early hours of the morning.

Supervisory and co-worker monitoring
In instances where operational demands require extended hours of work that may result in employees working through higher levels of fatigue than normal, employees and supervisors will be proactive in observing and acting on fatigue-related symptoms in one another. In cases where fatigue symptoms are repeatedly observed in an employee, the supervisor shall be informed and measures will be taken to allow the employee to take a break or a nap, or use other strategies to improve alertness (such as exercise, caffeine). Additional supervisory checks for safety-critical work will also take place.

Task rotation and task re-allocation
Rotation of tasks will be arranged during periods when operational demands may increase fatigue-related risks. Monotonous tasks with little variety will be targeted in particular. Supervisors will rotate work in consultation with concerned employees to ensure that all are assigned to familiar tasks. No employee shall be assigned to more than three different tasks during a given period.

In situations of increased fatigue-related risk, such as when an employee repeatedly exhibits symptoms of fatigue, it may be necessary to re-schedule or re-assign some tasks. Any task sensitive to the effects of fatigue should be re-scheduled or re-assigned. The list of risk factors below should be used as a guideline to identify activities that need to be rescheduled or re-assigned:

[List risk factors specific to the company.]

Additional breaks and strategic use of caffeine
When operational requirements call for longer hours of work, additional breaks of 10 to 20 minutes will be provided to employees on request. Employees are responsible for monitoring themselves and for requesting a break when they feel it necessary to restore their performance levels. Employees should also suggest breaks to co-workers if they observe fatigue symptoms. During these breaks, employees will take necessary actions to counter fatigue effects (exercise, drink caffeine, etc.).

It should be noted that since habitual use diminishes the stimulating effects of caffeine, [insert company name] does not promote regular use of caffeine. However, it can be useful in contingency situations to help increase alertness when required.

3.7 Reporting Protocols (Mandatory)

Reporting protocols within the FRMS should be defined on two levels:

  1. Reporting fatigue-related risk (insufficient sleep or sleep opportunity, fatigue-related symptoms)
  2. Reporting errors and incidents that are fatigue related

Reporting fatigue-related risk (recommended)

Reporting risk is important for FRMS review and evaluation. Collect data on the frequency that employees are at risk of fatigue-related error or incident. How often did the work schedule provide insufficient sleep opportunity? How often did employees report getting insufficient sleep? How often did they report experiencing fatigue-related symptoms?

Employees may be reluctant to report this level of fatigue-related impairment on formal incident reporting forms, particularly in the early stages of FRMS implementation. The company should ensure that employees are aware of the fatigue reporting policy and that reports submitted to the system remain confidential. A special reporting form may be appropriate. The company could set up a reporting system and fatigue occurrence database on the company intranet to collect information such as:

  • What schedule have you been working for the last week?
  • How much sleep did you obtain in the last 24 hours?
  • How much sleep did you obtain in the last 48 hours?
  • What fatigue-related symptoms have you been experiencing?
  • Have you notified a supervisor that you are at risk of making a fatigue-related error?
  • Who have you notified that you are at risk of making a fatigue-related error?
  • What countermeasures have you used?

Reporting fatigue-related errors and incidents (mandatory)

Most organizations have formal requirements to report errors and incidents as a part of their SMS. Few, however, systematically examine whether fatigue was a contributing factor. Industries that rely on shift work should develop standard reporting criteria that accurately reflect the occurrence of fatigue and sleepinessrelated errors and incidents.

For an error or incident to be defined as fatigue related, it must have:

  1. occurred in the presence of fatigue
  2. been consistent with fatigue-related error (e.g., caused by employee falling asleep, inattention, delayed reaction time, complacency, etc.)

In order to define an event as fatigue related, the first three levels of control (see the figure in Section 3.1) must be reviewed:

  1. Did the work schedule provide sufficient sleep opportunity for the employee?
  2. Did the employee actually obtain sufficient sleep?
  3. Was the event preceded by the presence of fatigue-related symptoms?

Examining planned and actual hours of work not only reveals whether changes led to insufficient sleep opportunity but can help the company better understand whether additional work hours were foreseeable and how to better allocate them in the future. Questions about the schedule could also include examining the commute to and from work for employees involved since this can also influence the sleep opportunity.

The second question allows the company to collect information on actual sleep obtained by the specific employee. How many hours of sleep did the employee obtain in the 24 and 48 hours before the event? How long was it since the employee had woken up from a sleep or a nap? If the employee had not obtained sufficient sleep, why not? Why was it not reported on arrival at work?

Since the reporting process relies heavily on the honesty of employees, it should be non-punitive. Incidents of insufficient sleep should be considered a learning experience for the organization and other employees, rather than as an incident that can affect an employee’s employment status.

The organization should also investigate whether the employee had been observed falling asleep or struggling to remain alert in the week before the event. This information could be collected either directly from the employee, or from co-workers or supervisors. Similarly, was the employee exhibiting any other fatigue-related symptoms directly before the event?

Additional questions that could be asked include:

  • Did the employee take medications or drugs in the week prior to the event?
  • Has the employee been diagnosed with or show symptoms of a medical problem or sleep disorder that may affect fatigue or alertness?
  • Did the employee work at another job or have additional responsibilities during the two weeks before the event?

Assessing the information collected with these questions can provide organizations with a clearer understanding of when fatigue is a contributing factor to an error or incident.

Reporting non-critical errors also offers an opportunity to analyse the effectiveness of the FRMS. In any organization, there is a greater frequency of errors than incidents. An organization can determine the root causes of any fatigue-related risk and implement appropriate control strategies before an error becomes an incident.

Points to Consider

  • What reporting structures are already in place within the organization?
  • What is the process for reporting potential risk from fatigue (as opposed to an actual event)?
  • What factors are to be investigated to determine whether fatigue was a contributing factor to an incident?
  • How can fatigue be better reported within the organization?

Sample Text

Section 3.7    Reporting Protocols (Mandatory)

[Insert company name] is committed to continually reducing the risk of fatigue. To achieve this, a structured data collection process records when:

  • An employee is at risk of making a fatigue-related error (i.e., provided with insufficient sleep opportunity within the schedule, actually obtained insufficient sleep, and/or exhibits fatigue-related symptoms)
  • Fatigue has been a contributing factor to a safety-related error and/or incident

Employees are required to report all cases of fatigue-related risk, errors, and incidents to their immediate supervisor. The supervisor will act accordingly, depending on the severity of the case. This may include (but is not limited to) advising the employee to self-monitor performance, allocating peer/management supervision to the employee, task reassignment, scheduling naps, or sending the employee home.

A confidential reporting database (Fatigue Occurrences) has been made available to all employees on the company intranet. The purpose of this database is to collect information on the frequency that employees: are provided with insufficient sleep opportunity (due to overtime or contingency situations); obtain insufficient sleep; exhibit fatigue-related symptoms; or make a non-consequence error that may have been fatigue-related. Although employees are required to provide their name, this will only be used by the safety manager if more information is required. The intent is purely data collection, and the information will not be used for disciplinary purposes.

All reports of errors and incidents will be made using the existing SMS reporting framework (refer to SMS policy document). During the error/incident investigation process, the investigator will ask any employees involved to provide an accurate account of hours worked during the two weeks prior to the event, how much sleep was obtained during the preceding 24 and 48 hours, and whether they were experiencing any fatigue-related symptoms. Colleagues and supervisors will also be asked whether they observed any fatigue-related symptoms in the employees involved.

In consultation with management and safety officials, the investigator will recommend short term corrective actions for preventing similar events, and factors to consider in the FMRS review process.

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