An observational objective job analysis of role related tasks undertaken by Royal Navy sailors

1 Introduction

The Royal Navy (RN) is the United Kingdom’s maritime fighting capability, able to conduct complex operations on and from the sea. Operations range from small scale security patrols and humanitarian missions to multinational combat exercises [1]. British maritime doctrine stipulates a requirement for a suitably staffed and trained Navy to provide the means to fight at sea. As such, the RN routinely undertakes sea deployments and training activities to ensure personnel are duly trained and combat ready. These deployments utilise a variety of platform sizes dependant on the individual mission objectives and are often undertaken in isolated and sometimes austere settings. Deployments can last many months, and are often carried out at far reach, with limited opportunity for resupplies or crew changes. Therefore, RN personnel are required to possess complex knowledge and technical skills, in addition to the physical and mental capacity to undertake their roles. The RN expects it sailors to be physically capable of undertaking a wide variety of sea-faring tasks requiring a range of physical attributes. At present the RN tests the physical capacity of its sailors on an annual basis with the Royal Navy Fitness Test (RNFT), detailed in Table 1.

The utility and legitimacy of the current RNFT has been questioned [4]. In particular the use of an unloaded aerobic assessment for an occupational task requiring load carriage (firefighting breathing apparatus) represents a potential limitation. The most recent Subjective Job Task Analysis of critical and demanding RN seafaring tasks failed to identify any single task that was wholly dependent on unloaded endurance, and as such a fitness standard which predominantly tests this aspect of fitness is likely inappropriate [5]. A review by Taylor et al., [6] suggests a better approach than generic, unloaded field-based tests is the implementation of a test which would allow the simultaneous assessment of multiple components of fitness (i.e., muscular and aerobic endurance). Furthermore, it is suggested that the clothing worn during such tests should reflect the occupational specific clothing within the criterion task.

Under the U.K. Health and Safety at Work Act 1974 [7], employers, including defence organisations, have a duty of care to ensure their personnel possess the physical capacities to undertake their work safely. Organisations with roles requiring individuals to engage in physically demanding tasks will routinely develop and implement job specific Physical Employment Standards (PES) to safeguard workforce health [8]. As previous work has highlighted the importance of physical endurance and physical strength in role-related tasks undertaken in physically demanding occupations, including military service [9, 10], the RN PES should ensure consideration is given to both these attributes.

Several frameworks have been proposed to assist organisations in developing new PES [11–19]. These frameworks have many similarities, where they generally seek to; 1) correctly identify the critical job-tasks, 2) ascertain the minimum acceptable job performance criteria (often using subject matter experts (SMEs); and 3) provide an auditable evidence base to support the findings. As such, the development process for PES must ensure legal defensibility through appropriate demonstration of the proportionality and legitimacy of the conditions of service being assessed and their associated minimal performance standards. In 2019 the Human Factors and Medicine Panel of the North Atlantic Treaty Organisation (NATO) published advice for designing and implementing PES, providing agreed definitions and terminology, establishing a standardised, evidence gathering framework, which would minimise inherent sex bias [19]. The RN has adopted the NATO methodological approach to provide an iterative, auditable trail of the research and military decisions that will form the cornerstone of the new RN fitness standard (RN PES). Thus, the research programme comprised four phases (Fig. 1).

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Fig. 1

An outline of the Royal Navy Physical Employment Standards Work Programme.

Phase-1 in the RN PES process generated a descriptive task list of 14 Criterion, role-related tasks using focus groups and surveys [5]. The generated task list reflected the most critical and physically demanding tasks that any sailor, irrespective of rating/rank or specialisation, might undertake during a sea deployment. To further refine the job task list, the present study aimed to; 1) quantify the most physically demanding tasks undertaken by RN sailors, 2) further refine and define the generic task descriptions into specific role-related tasks, and 3) identify the most demanding and important tasks to progress to the next phase of the RN PES research programme.

A between-subjects, Objective Job Task Analysis was performed on 14 Criterion Tasks as part of a Service Evaluation in accordance with Ministry of Defence Research Ethics Committee policy [20]. Written informed consent to take video and photographic evidence during each observation was received from participants prior to undertaking observations. The 14 Criterion Tasks from the Subjective Job Task Analysis were clustered into eight groups; ‘ammunition ship’, ‘humanitarian assistance’, ‘ship embarkation’, ‘damage control’, ‘firefighting’, ‘casualty handling’, ‘abandonment’ and ‘generic –other’ (Table 2). Each task-group was evaluated separately during RN training exercises.

2.2 Objective job task analysis

Twenty-one task observations were performed during training exercises across RN Type 23 Frigates, Type 45 Destroyers, and shore-based training facilities. All observations reflected the business-as-usual training activities. In total, 203 RN personnel (age 28±7 years) were observed with between 1–49 service personnel undertaking each task or task variant. The sample was diverse in terms of sex (16% females) and ranks (56% Able Seaman; 15% Leading Hand; 7% Petty Officer; 8% Chief Petty Officer; 2% Warrant Officers; 2% Sub Lieutenant; 5% Lieutenant; 5% Lieutenant Commander).

2.2.1 Cardiovascular demand

Cardiovascular demand was quantified during tasks from a chest-worn heart rate (HR) monitor (Polar Team 2, Polar Electro Ltd, Warwick, UK) supplied and fitted by the research team before each observation. Data were downloaded to Polar proprietorial software and inspected for artefacts; suspect (non-physiological) data were cleansed via a lower and upper boundary filter. Due to limited access to personnel undertaking the training activities, maximum HR (HRmax) was estimated from a previously published equation (Equation 1 [21]).

Equation 1. Calculation of predicted maximal heart rate (HRmax). HR max = 208 - 0.7 × age

Due to the large variation in Criterion Task duration, summary data were calculated and expressed as percent time spent in six zones based on estimated % HRmax (i.e., <50% HRmax, 50–59% HRmax, 60–69% HRmax, 70–79% HRmax, 80–89% HRmax, ≥90% HRmax). In addition, mean HR and peak HR were calculated for each task and expressed as a percentage of HRmax. Mean and peak HR were defined as the average and the highest values obtained from a rolling 30 s average, respectively.

Similar to work by others [16, 23], three HR metrics were used to rank tasks based on their cardiovascular demand. These included mean HR, peak HR, and the percentage of time spent above 80% HRmax. Tasks were ranked individually for each HR metric and the compound rank score for the three HR metrics determined the overall task rank (Equation 2).

Equation 2. Calculation of Cardiovascular Demand Compound Score: HR Compound Score = mean HR ranking + peak HR ranking + 80 % HRmax ranking 3

2.2.2 Task characterisation

Task characterisation and observational movement analysis (e.g., primary physical action, mass moved and distances) were conducted during and after task observations. The masses of equipment and objects were measured with digital scales to the nearest 0.1 kg (Seca 770, Seca Ltd, Birmingham, UK) after each observation. The mass of Personal Protective Equipment (PPE) ensembles (e.g., firefighting equipment) were measured by subtracting the participants body mass from their total mass whilst wearing the PPE before each observation. Similarly, the object mass carried during team-based tasks (e.g., two-person casualty carry) was measured by subtracting the participant’s body mass from their total mass whilst lifting an object during static trials after observations of the dynamic task. The height of objects and the dimensions of spaces were measured with a laser distance meter (CP-100 S) or a tape measure to the nearest 0.01 m after each observation. The ship environment precluded the use of Global Positioning Systems (GPS) to measure distance and speed of movement. Consequently, horizontal distances were measured following each task observation by re-tracing the route taken with a laser distance meter. Video (Sony HDR –CX405; MUVI K-Series K2) and photography (Sony DSC WX350) were used in combination with hand notation to capture task ergonomics and analyse task speed, distances and volume (repetitions). The speed of movement was calculated retrospectively by reviewing the video recordings and timing movement over known (measured) horizontal distances. A hand notation proforma was completed by researchers for each task observation to detail the: exercise, scenario, Criterion Task, participants, clothing/PPE and equipment, as well as start and finish times, number of personnel involved, distances moved, compartment dimensions and repetitions performed.

Task characterisation was based on previously published methods [22]. The metrics used to characterise the tasks included: duration; object mass; number of personnel involved; number of hands used to handle the object; clothing/PPE worn; time-criticality; vertical lift height/distance; number of decks transited; horizontal carry distance; number of lift/carry repetitions; work: rest ratio; ambulatory speed; and repetition rates. Following task observations, each task was classified into one of four, primary physical actions, which included: ‘vertical lift’; ‘locomotion with load’; ‘push/pull’; and ‘other’ [22]. Subsequently, tasks were clustered into sub-groups, which served two purposes: first, to ensure the entire continuum of role-related functional movements were represented in the subsequent phase of the programme (i.e. physical demands analysis); and second, to identify common, fundamental physical actions to generate generic role-related PES assessments that could be modulated for different RN trades, or fighting arms in the future. Task sub-groups are highlighted at Step 2 in Fig. 2.

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Fig. 2

The Seven Step Algorithm used to Down-Select Criterion Tasks.

2.2.3 Questionnaires

A separate Service Evaluation was conducted on RN Physical Trainers (PTs) (n = 72), who were invited to complete a questionnaire that aimed to elucidate which components of physical fitness (i.e., aerobic endurance, anaerobic endurance, muscle strength, muscle endurance and mobility) were influential in determining Criterion Task performance. Definitions of each component of physical fitness were provided, and for each Criterion Task were ranked by PT staff in order of importance on a 5-point Likert scale. An example of the questions asked, and rating scale can be found at Table 3.

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Table 3

An example of the PT branch questionnaire – which was used to establish the most important component of fitness within each Criterion Task

For the Criterion Task _________{insert task name here}_________ please rank the below components of fitness in terms of their importance within the successful completion of the task. Where a ranking of 1 is for the component of fitness that is least important, and a ranking of 5 is for the component of fitness that is most important within that task. Please refer to the component of fitness descriptors which have been provided if needed. Use each rank score (1–5) only once, so each component of fitness has a unique score (ranking) below.
Component of fitness:	Aerobic Endurance	Anaerobic Endurance	Muscular Strength	Muscular Endurance	Mobility
Ranking (1–5):	1	1	1	1	1
	2	2	2	2	2
	3	3	3	3	3
	4	4	4	4	4
	5	5	5	5	5

2.2.4 Final selection

The final tasks selection was made by the MJP and was based on a logical stepwise approach considering all aspects of task physiological demand, task ergonomics and organisational requirements (Fig. 2). The final task outcome (selection or exclusion) was reached by a consensus view of the MJP members once all relevant information had been discussed. Each task sub-group (Fig. 2; Step 2) was considered independently to ensure a wide breadth of movement profiles were included in the final task list.

2.2.5 Statistical analysis

Physiological data were checked for normality by assessing skewness and kurtosis, and unless stated presented as a mean±one standard deviation (SD). Where data were available for a singular task across multiple observations, data were pooled into a single sample. Descriptive statistics on task ergonomics were generated for each of the 36 tasks and were presented to the MJP to aid decision making.

3 Results

The purpose of this present study was to complete an Objective Job Task Analysis of Criterion Tasks performed by RN personnel. The overall aim of the study was to identify only the most physically demanding and critical tasks undertaken by RN sailors, but which would still provide a wide breadth of movement profiles and physical demands to be tested. This work provides an evidential record of the physical demands of 36 ship-board activities undertaken by RN sailors and has elucidated a list of the 14 most physically demanding and unique tasks.

The combination of task observation HR responses, task functional movements and a MJP resulted in the down-selection of 14 Criterion Tasks to progress on to the physical demands analysis phase of the programme. Consequently, six Criterion Tasks from the Subjective Job Task Analysis and 22 task variants from the Objective Job Tasks Analysis were excluded and will no longer be considered in the development of the RN PES.

During observations new task variants and roles emerged, as such, the size of the task list was not reduced following completion of this phase of work. This outcome will add complexity and challenge to the next phase of the research, as it is customary for a PES task list to reduce as the PES process develops, allowing greater focus to be placed on the most relevant tasks from which a PES will eventually derive [19]. The increase in the task list can be explained by the varied, complex and team-based nature of the tasks observed. For example, the task ‘ammunition ship’ varied depending upon the type of ammunition handled (e.g., 4.5 shells, 30 mm boxes) and the location of the ship the activity was performed (e.g., upper deck, deep magazine). Furthermore, five physically demanding tasks were observed during the task ‘disaster relief’, which included tasks such as casualty handling/rescue and movement of essential equipment and provisions.

Comparatively, in the development of the Royal Australian Navy PES, 29 tasks were observed (38 task variants), versus 20 tasks (36 variants) in the present study [23]. A process of down-selection and task combination resulted in the Royal Australian Navy PES task list reducing from 29 tasks to four scenarios (i.e., ‘storing’, ‘fighting a fire’, and two variants of ‘toxic hazard teams’). Each scenario comprised one to six tasks from the original task list. Consequently, in the next stages of the RN PES development, scenarios should be developed combining multiple tasks from the current task list. This will reduce the required number of observations and promote greater ecological validity –especially in terms of task duration and aerobic demands.

Muscular endurance and aerobic endurance were rated as the most important components of fitness across all the essential Naval tasks. Furthermore, muscular strength was also identified as an important attribute. It has been previously shown that physical endurance and physical strength influence performance in many tasks undertaken in physically demanding occupations [9] and are important in the development of military readiness [10], which the RN PES data support. Additionally, a recent Royal Marines job task analysis also reported a breadth of physical fitness components (e.g., aerobic, anaerobic, muscle endurance, muscle strength, mobility) that underpinned role-related performance [24, 25]. Hence, in military occupations there is a justification to test a broad range of fitness components. Muscle endurance appears to be highly influential in RN role-related task performance, and therefore should be central to the future RN PES. The importance of other components of fitness should not be overlooked, particularly when considering the eventual configuration of the test(s).

The task down-selection in the present study was performed with a ranking system that considered both task HR responses and a full spectrum of role-related task functional movements. This has ensured that both cardiovascular and a breadth of manual material handling role requirements are considered in the next phase of the programme. The placement of tasks in a rank order meant that the stringency (or leniency) of the task down-selection could be modulated so that an appropriate number of tasks were taken forward to the next phase. A bespoke approach ensured that the tasks down-selected exhibited: the highest cardiovascular demand; a breadth of functional movements/requirements (e.g., vertical lift, locomotion with load, push/pull); embarked tasks; the prioritisation of ‘time-critical’ tasks; and tasks that included the additional burden of firefighting PPE.

Of the 14 tasks down-selected, five were selected based on HR responses; three based on the functional movement of ‘vertical lift’; eight involved ‘locomotion with load’; one ‘push/pull’; one ‘climb’; one ‘swim’ and one ‘unloaded locomotion’. Crucially, a comprehensive representation of the different functional movements performed on a sea deployment emerged from the task down-selection. Clustering the Criterion Tasks into different types of functional movement has strategically prepared the RN PES programme to implement a PES that should be able to predict role-related performance amongst different RN trades, fighting arms and specialisations [22]. The adoption of this approach may allow the final RN PES to contain modular aspects, where simple adjustments or additions to the generic assessment (e.g., a greater mass lifted) may better reflect the enhanced or unique physical requirements of RN specialisms (e.g., Navy Divers).

There were several limitations in this study. First, a between-subjects design was undertaken, which meant that within-subjects, repeated measures comparisons of task HR responses could not be performed. Second, the sample size of the task observations varied considerably. However, this was in-part an unavoidable consequence of the size of courses/training exercises and the nature of the tasks (e.g. one-person task versus team-based task). Third, certain training exercises appeared to have an unrealistically low physical demand that was due to: at times a surplus of available personnel to perform tasks; a casualty dummy that was unrealistically light (i.e., 37 kg); and the use of uncharged firefighting hoses during ship-based training exercises. Lastly, due to health and safety or for public health reasons it was not possible to measure HR in all tasks, meaning the cardiovascular demands of these tasks could not be appraised. Despite the limitations, significant data were gathered and presented to a MJP to evidence the physical demands and physical requirements of generic tasks performed by RN personnel to progress the development of the RN PES.

5 Conclusion

This Objective Job Task Analysis identified 14 critical and demanding tasks that could be undertaken by a RN sailor during a sea deployment. The task list encompasses a wide breadth of physically demanding tasks (e.g., ‘firefighting’, ‘casualty handling’ and ‘response to flooding’), across a range of unique movement profiles. Further, we have demonstrated that it is feasible, and ecologically more valid to establish the demands of naval seafaring tasks in their occupational context –where we have been able to measure a number of different components of fitness to inform the RN PES. Future work will look to exploitthis task list, to develop job related scenarios that comprise several tasks, to yield scenarios which have greater ecological validity with respect to a ‘reasonable worst case’.

Ethical approval

This work was undertaken as a service evaluation in accordance with the Ministry of Defence Research Ethics Committee regulations. As such there is no ethical approval number.

Informed consent

Participants provided written informed consent in accordance with the Ministry of Defence Research Ethics Committee regulations.

Conflict of interest

None to declare.