HUMAN FACTOR DESIGN IN UK DEFENCE
5. WHAT HF PROCESSES ARE USED BY
HFs are an intrinsic part of System Engineering that establishes a process to define how a system satisfies the user requirements and constraints through the development of functional characteristics that are decomposed into system component descriptions and interfaces that can be verified as satisfying the system requirements. System integration is a key activity that establishes how the functional requirements and characteristics have been implemented in the physical solution. Within the System Engineering process HF is a methodology to ensure that the Human Component is correctly represented and used appropriately. The following HF Activities and Analyses are indicative of those suggested by JSP 912 [3], MAP 01-010[4] and Def Stan 00-250 [5].
HF Activities - Warship Specific
Manpower, Complementing and Accommodation
Team Organisation
General Arrangement, Operational Spaces
Accommodation Spaces, Miscellaneous Spaces
Personnel Movement and Material Handling
Habitability and Internal Environment
Maintenance and Support HF Activities - Generic
Understand the Context of Use
Define the Organisation’s Characteristics
Validate User Characteristics
Develop Job/Role/Task Design
Identify Training Needs
Allocate which Functions are met by machine or People
Design Human-Machine Interfaces
Equipment designed for People
Environment designed for People
Develop Safe Systems HF Analyses
Task Analysis
Workload Analysis
Link Analysis
Person-to-person Communications Analysis
Person-to-machine Communications Analysis
Allocation of Functions Analysis (between People and Equipment)
Human Performance Analysis
Human Reliability Analysis.
5.1 REPRESENTING THE MILITARY HUMAN The following are approaches as to how military humans are represented to manage their use at all levels of the ship organisation.
5.2 TARGET AUDIENCE DESCRIPTION (TAD) The TAD is compiled by Projects to reflect the type of people, represented by physical characteristics, knowledge and skills, which will be used within the solution throughout its life. Once defined it is used by designers when selecting the most appropriate person to carry out a role required by the design solution. Some solutions may require special skill adaptations that are identified through Training Need Analysis. These special skills are costly to deploy since they increase the overall training burden. Many of these expensive training needs can be replaced by systems developed to use just core skills. As with many military systems, workload must be set at a sustainable level for all operational scenarios.
Good systems recognise the human characteristics that limit performance at individual, collective and organisational levels.
A significant aspect of accommodating service personnel is the large amount of anthropometric data that must be reviewed to ensure all shapes and sizes can perform all of their position tasks and personal functions. Ships are sized generally for the 5th to 95th percentiles of the male and female population. Figure 1 describes some of the range of human physical attributes.
5.3 OVERARCHING PEOPLE-RELATED REQUIREMENTS (DEFSTAN 00-25 PART 1)[5]
This is a set of requirements that can be tailored to suit specific projects. They are deployed in the URD and SRD to ensure that solutions are developed with people in mind. The following list outlines the scope of the requirements.
Figure 1 People Characteristics (DefStan 00-250 Part 3 Section 9) [5]
People in Systems
Allocation of Functions
People Characteristics
System Safety
Training
Operations, Maintenance and Support
The Workplace
The Environment
Work Equipment
Living Spaces (important for RN )
The following is a typical example of the requirements.
8.4.10 Living Spaces
OPRR 85 The Solution Provider shall demonstrate that all living spaces and associated sanitary facilities, including those for ablution, excretion, and personal equipment maintenance that comprise, or are modified by the Solution are designed to meet functional and people-related needs.
The term Living Spaces shall include:
a) sleeping rooms;
b) dining rooms;
c) ablution, sanitation and toilet spaces d) recreation rooms and areas;
e) access, passageways and lobbies;
f) physical training areas g) training spaces h) education spaces
The following characteristics are described.
Physical Aspects
Body Size
Static Anthropometric Data
Dynamic Anthropometry
Dynamic Range of Movement
Strength
Stamina
Effects of Age
Gender Differences
Posture and Work Capacity
Fatigue
Dexterity
Hearing/Audition
Human Speech
Non-Verbal Communications
Person to Machine Non-Verbal Communication
Psychological Issues
Perception
Human Error
Stressors
Principles of Vision
Principles of Touch
Principles of Smell
6 HF IN THE NAVAL ARCHITECTURE
DOMAIN
Whilst system complexity is dominated by Combat, Command and Control Systems the Platform that delivers and supports them has many HF areas that are the responsibility of Naval Architects. These HF areas comprise of personnel functions such as Husbandry, Habitability, General Arrangement, Escape and Evacuation and Performance at Sea.
6.1 SHIP HUSBANDRY.
Ship Husbandry is an unusual term in that it implies that something in the ship needs to be cared for and nourished. It is not about caring for Navy personnel directly, that is a function of the Executive Officer and the Ship's medic, but the activity does benefit the Ship's Staff. Ships Husbandry is all about maintaining the condition of the common areas within the ship and its weather decks. It includes the maintenance of paint coatings, deck fittings, vents, jalousies, scuppers, stantions, doors and their furniture, deck coatings, vent filters and many other important parts of the ships infrastructure that need attention whilst away from homeport. The most onerous of these Husbandry activities is the cleaning of the ship's estate by Junior Rates. The most common cleaning activity is the washing and rinsing of floor coverings that are found throughout the ship. The cleaning activity is not helped by the material of the deck coverings that must be manufactured to emit low smoke and toxins in the event of a fire. The resultant "drudgery" is well known as a factor influencing the well being of junior staff that are known to resign early to escape the hard regime.
So where is the HF in Husbandry? It’s mostly about materials that are fit for purpose and equipment that requires little or no maintenance. Its sounds simple but because of the quantity of these items around the ship any shortfalls impact directly on Ship's Staff workload.
Typical "sore thumb" areas are watertight door catches that wear prematurely and deck coverings that wear out and require more cleaning effort. As ever attention to detail pays handsomely!
6.2 HABITABILITY.
Habitability is a broad term that captures the quality of the living experience. It’s about the homely aspects for all on board where comfort, nourishment and relaxation are available when duties cease. Again there are special measures to limit the effects of fire and smoke for all the materials used such as mattresses, bed linen, curtains and cushions. Living accommodation is always a topic of conversation for ship's staff, after all it’s their home for 6 months or more . The pressure to manage the cost of accommodating all on-board and the direct influence it has on the initial and through life cost of the ship (UPC and Salaries) makes for a difficult compromise. Each
Project must balance the accommodation standard with the attitudes and expectations of young staff that expect more and the through life and build cost.
6.3 GENERAL ARRANGEMENT.
The General Arrangement is the product of the whole ship design process. In the Concept Phase the design is based on space and area demands that are calculated from similar ships. Initially there is no need for a General Arrangement since costing can be accomplished using parametric and regression data to arrive at an initial estimate. The Project may create many design cases to determine cost drivers for given capabilities. Once the cost/capability argument is satisfied a General Arrangement can be created to reflect the equipment decisions and initial numbers of personnel to be accommodated. Now we can talk in HF! There is potentially everything to consider and every requirement to satisfy.
The General arrangement is a means to validate potential solutions by showing that all equipment and personnel that are to be housed have an allocation of space and are positioned correctly within it. It cannot validate spaces where human activities occur without more detailed studies but an assessment of escape following fire or floods can be made. In terms of arriving at manpower numbers the driving activity is damage control and fire fighting where the ship relies on manpower and equipment to avoid total loss. The ever present demand to reduced manpower must be achieved by reducing the manpower burden required for the damage control and fire fighting system. Manpower can be reduced by increasing automation of the systems, this leads to more system complexity at the expense of recoverability.
Whilst the cost of automation can balanced by the manpower savings there appears to be a state at which overall survivability is plateaus whilst costs increase.
6.4 ESCAPE AND EVACUATION.
This area is rich in HF requirements, after all we are trying to leave a ship that can no longer sustain life.
Effective escape requires information, training and robust systems to ensure that when the time comes the ship's staff are protected until they reach a place of safety.
There are ship systems that contribute to escape and equipment designed specifically for evacuation. The ship designer's main concern is about providing useful escape routes to the upper decks. These can conflict with other requirements such as security where escape may be impeded. Human characteristics are used in escape analyses to determine escape times. These were derived by trials on the DRIU and HMS BRISTOL. Training for escape is also a requirement that takes place ashore and on-board during Officer Sea Training.
6.5 SHIP ACCOMMODATION DESIGN.
Warship accommodation for junior ratings has progressed from 50 man messes to 6 man messes within the last 35 years. For most of this time the then guidance for accommodation, NES 107, was never fully met by successive warship projects. The principle reason being that the pressure to deliver warships to budget, something never really delivered but that’s another story, was managed by lowering the junior rate accommodation standard that significantly influenced the size of the ship and thereby its overall cost.
The old standard was very prescriptive, with floor areas defined for each rank, none of which was attributable to personal needs. Projects that moved away from the standard found that area decisions were made in the absence of any issues that would arise as a consequence such as not enough room to change in the mess. Another factor was the practice of planning to operate new warship classes with "reduced manning" again to satisfy budgetary targets. This approach resulted in ships being heavily modified once at sea to provide enough accommodation for the numbers actually needed onboard.
Having absorbed this lamentable reality I set about defining a functional approach to warship accommodation that would enable future projects to justify accommodation standards based on space allocation derived from living activities such as dressing, washing and sleeping. The approach was set around four main functions of protect, sustain, health and develop.
Each function was assigned derived requirements that all solutions would deliver such as heating, ventilation, lighting and access.
The accommodation design process follows the CADMID cycle as defined in Part 1, whilst Part 2 contains the functional areas and how they are satisfied.
6.6 HUMAN PERFORMANCE AT SEA.
Traditionally this topic focused on motion induced interrupts (MII) to body stability and motion induced sickness (MIS). The subjects are considered by the ABCD Group of international navies. Recent research by the Institute of Naval Medicine on behalf of the MOD has studied the performance of RN personnel at sea with a diary completed each day to record the effects of ship motion on performance.
6.7 WHOLE BODY VIBRATION.
Since the Control of Vibration at Work Regulations (COVAWR) was published in 2005 I have been alerting projects to the fact that it specifically includes military personnel unlike other safety legislation that usually exempts them. The COVAWR has proved to be a blessing in disguise for military personnel for two
reasons. Firstly the health monitoring activities are useful for personnel that experience high and sustained exposures, predominately in high speed craft, for identifying acute or accumulative injuries before they can cause disabling permanent conditions. The other reason is enhanced military capability brought about by newly introduced body conditioning exercises that enhance individual's abilities to withstand shock and vibration exposure and advanced coxswain training to minimise vibration exposure through route selection, throttle and helm control. In the future advanced hull forms will be introduced to further reduce shock and vibration exposure. My contribution to this area is to research the benefit of posture for coxswains and passengers. The research will explore a range of seat back and base configurations to minimise exposure whilst being able to perform command and control functions. Exemplar seats that can be configured to provide a range of postures shall be integrated with typical controls and instrumentation to determine optimal seat back and base configurations. The results will provide future high speed craft projects a means to identify optimal seating configurations that fully integrate with the crafts cockpit location and structures.