NVIC 04-89: Introduction to human factors engineering

United States COMDTPUB P16700.4 Coast Guard NVIC 4-89 27 NOV 1989 NAVIGATION AND VESSEL INSPECTION CIRCULAR NO. 4-89 Electronic Version for Distribution on the World Wide Web Subj: Introduction to Human Factors Engineering Ref: (a) American Society for Testing and Materials F 1168-88, Standard Practice for Human Engineering Design for Marine Systems, Equipment and Facilities (b) Military Standard 1472.C, Human Engineering Design Criteria for Military Systems, Equipment and Facilities

Introduction to Human Factors Engineering — PURPOSE. This Circular introduces Human Factors Engineering (HFE) and describes and

encourages its application to design, construction, overhaul, and maintenance of vessels. Areas where immediate cost effective changes can be made to improve safety and operating efficiency within the marine industry are illustrated.

Introduction to Human Factors Engineering — BACKGROUND.

a.

Definition.

HFE is the specialized engineering discipline concerned with ensuring systems (equipment and software) are designed to match the capabilities and limitations of the personnel which will operate and maintain them.

HFE combines knowledge of human mental and physical capabilities and responses with traditional engineering principles and procedures to design machines and systems, such as ships, from the user's point of view.

HFE builds upon the disciplines of physiology, psychology, sociology, and engineering.

Physiology, the science dealing with the size, shape and physical functioning of humans, provides empirical data about the human body and senses.

This information is needed to ensure an appropriate physical interface between man and machine.

Psychology, the knowledge derived from a careful examination of consciousness and behavior, provides information on how an individual will respond to an environment, or in a given situation.

Sociology evaluates how an individual performs as a member of human society, or a member of an organization or group, such as a ship's crew.

This information, when combined with knowledge from traditionally technical fields such as mechanical engineering, industrial engineering and computer science/engineering, enables the Human Factors Engineer to predict how well an individual will perform in a given environment and how to design a work environment which will enhance efficiency and safety.

NAVIGATION AND VESSEL INSPECTION CIRCULAR NO. 4-89 A very important part of HFE is providing more effective and safer man-machine interaction.

The application of HFE to the marine industry can create work environments which ensure effective work patterns contribute to improved personnel health and safety and minimize factors which degrade performance or increase human error.

This is accomplished by applying structured methodologies, based on historical and empirical information, to evaluate factors such as workload, accuracy, physical stress, visual or auditory perceptiveness, and time constraints.

This information would then be used to ensure that work requirements do not exceed human capabilities.

HFE is sometimes referred to as Human Factors (HF), Ergonomics, Engineering Psychology, Human Engineering (HE), Bio-technology, or Man-Machine Systems Engineering by members of the profession.

Courses relating to Human Factors are offered at numerous universities and colleges leading to bachelor and advanced degrees. b.

Components.

The discipline of HFE is composed of six individual concentrations or elements, which cover a broad spectrum of physiological and psychological concerns.

These six elements are:

(1) Human Engineering (HE) - The application of human physiology and psychology to the design of equipment, work stations, consoles, controls, displays, software, and the complete system or facility.

(2) Biomedical - The application of biological and medical knowledge on design to promote the health, safety, protection, sustenance, escape, survival, and recovery of personnel under normal and emergency conditions.

(3) Manpower/Personnel - Identifies the predicted and/or acceptable range of human characteristics and the required number and skills of personnel needed to install, operate, and maintain equipment, systems, or facilities.

(4) Training - Identifies training requirements, develops curriculum and related instructional materials, specifies essential training aids, and designs threshold tests to provide competent personnel to operate and maintain the equipment,

(5) Publications/Documents - Assures operating and maintenance documentation is appropriate for the expected users.

(6) Test and Evaluations - Verifies that users, equipped with the appropriate instruction, tools, and documentation, can effectively and safely operate and maintain the equipment, Systems, or facilities within the full range of expected operating environments. c. History. The term "Human Factors Engineering" is of recent origin, first used in the 1940's. However, HFE concepts can be found in earlier works, such as Adam Smith's "Wealth of Nations" (1776), in which he described the principle of "division of labor," and Charles Babbage's "Economy of Machinery and Manufacture" (1832) which discussed methods of making workers' jobs easier. Time study experiments conducted by Frederick W Taylor (1900-1910), and time and motion studies of assembly operation by Frank and Lillian Gilbreth (1910 - 1920), became the basis for analytical tools still used today. NAVIGATION AND VESSEL INSPECTION CIRCULAR NO. 4-89 The 1940's and World War II brought the first great advance in HFE. As weapons systems became increasingly more complex, it was recognized poor HFE resulted in the loss of lives and poor performance. American aircraft manufacturers studied aircrew body sizes in designing bomber escape hatches and reduced accidents by changing the sizes and shapes of knobs on control handles. In 1947 what many consider to be the first HFE textbook was published, Applied Experimental Psychology (Chapanis, Garner and Morgan). In recent history, the Department of Defense (DOD) has initiated two significant efforts in HFE to address concerns with the increased complexity of weapons systems and the decreasing number of persons entering the military. These efforts are:

(1) HARDMAN - This study produced an analytical methodology for determining manpower, personnel, and training requirements for specific equipment and systems. The focus was to determine the education, experience, and skills required to operate and maintain existing or new equipment and systems.

(2) MANPRINT - This effort involved the application of HFE to the material acquisition process. The focus of MANPRINT was to influence systems design during the earliest phases of life cycle system management. Many industries have been using HFE in the design and operation of their products and systems, including: computers, automobiles, aircraft and aerospace, home appliances electronics, medical equipment and electric power companies. Human Factors Engineering is of increasing importance to the Department of Defense. The merchant marine fleet is only just beginning to make use of HFE information and technology. d. Professional Organizations. There are numerous professional organizations for human factors engineers and social scientists interested in the human factors field. The largest, but by no means a complete listing, are:

(1) The Human Factors Society P.O. Box 1369 Santa Monica, CA 90406

(2) The American Psychological Association, Division of Applied, Experimental and Engineering Psychologists 1200 17th Street, SW Washington, DC 20036

(3) Systems, Man and Cybernetics Group of the Institute of Electrical and Electronics Engineers (IEEE) 345 East 47th Street NY, NY 10017 e. The HFE Point of View. In the design and operation of ships and their systems, consideration is given to the interface of humans and machines. The human is the most complex component in the ship/system interface. Designing equipment or software to be used on a ship without considering the humans who will install, use and maintain them usually leads to less than an optimum match between the human and the machine. The HFE approach is a philosophy which attempts to design things from the user's point of NAVIGATION AND VESSEL INSPECTION CIRCULAR NO. 4-89 view by taking into account the ordinary attributes of actual users. Consideration is given to: level of education; training which will be necessary to effectively use the system; access requirements and human physical size; physical environment; human tendencies to become bored and ineffective when performing routine tasks; and the human ability to reason inductively and make decisions in unusual circumstances. HFE can be refined to a set of principles, some of which are presented in this Circular. The following four questions embody the HFE philosophy.

(1) What does the human being do to operate or maintain the system?

(2) What is the worst case condition under which this hardware might be operated?

(3) What is the operating environment?

(4) What capabilities does the operator have and/or need? Asking these Four Questions is an assessment process. The answers may not be readily apparent but will provide information needed for HFE design and to make "tradeoff” decisions during design and construction.

Introduction to Human Factors Engineering — DISCUSSION.

a.

Introduction.

Advances in technology, shrinking profit margins and escalating manning costs are present trends within the marine industry.

Responses to these conditions have included increased automation and decreased crew sizes.

When plans for a smaller crew are included in new vessel design and construction, automated systems can be developed to compensate for the reduced manning, and a safe, efficient work environment can be created.

Many owners and operators have responded to these trends by proposing reduced crew sizes on existing vessels without considering the number of people required to perform necessary normal and emergency duties.

In reviewing these proposals, the Coast Guard must satisfy itself that the proposed crew reduction would not result in an unsafe working environment or an inability to respond to significant fire or flooding emergencies.

The application of HARDMAN and MANPRINT by DOD, particularly the Navy, has shown that changing the crew mix or reducing crew size, without changing equipment design, may result in an inefficient and unsafe environment.

This section describes how HFE may be applied to create safe and efficient working environments on new vessels and to improve safety and efficiency on existing vessels. b.

Principal Benefits.

The principal benefit of HFE is the reduction of human errors.

Studies by the Coast Guard, the National Transportation Safety Board (NTSB), DOD, and international classification societies indicate 50 to 80% of all marine casualties can be attributed to procedural or other types of human errors.

These errors are very costly in terms of lives lost.

Aboard U.S. inspected vessels alone, there were 63 deaths in 1986 and 58 in 1987.

Damage to U.S. inspected vessels and their cargo was reported at $191 million in 1986 and $199 million in 1987.

The reduction of some human errors through the application of HFE principles has the potential of creating cost savings well worth the investment.

Direct results will be increased productivity, reliability and operator usability (i.e., minimization of training and manpower costs.

In addition to reduction of human error, the Naval Research Advisory Committee (NRAC) has estimated that including human elements in the initial design phases of ships and equipment could improve their effectiveness and availability by 30%, survivability by 15% and reduce the NAVIGATION AND VESSEL INSPECTION CIRCULAR NO. 4-89 number of casualties by 10%, while reducing personnel by 20%.

The percentage of improvement within a military or commercial organization will vary; however, these figures illustrate the potential of HFE.

In addition to increasing efficiency and safety, use of HFE principles will improve living and working conditions aboard ship. c.

Uses for HFE.

HFE can be applied to accomplish the following tasks.

This is a partial list and is not meant to be complete.

(1) Most advantageous arrangement and layout of the bridge or other compartments and spaces.

(2) Design of automation monitoring and control systems for increased usability.

(3) Arrangement of console panels, including identification and design of important gauges, meters and control switches.

(4) Sizing, positioning, shaping, and sequencing of operating levers, controls and alarm systems for maximum reliability under stress and work overload.

(5) Determination of manning levels for safe and efficient vessel operation.

(6) Determination of desired skill levels and training requirements for crewmembers, leading to better training and reduced training time.

(7) Providing easy to read manuals or emergency operating instructions (COW Manual, Cargo and Ballasting Manual, Stability Information, C0 Operating Instructions, etc.) with simple explanations and diagrams.

(8) Task analysis of any given operation to determine the most efficient and safe method(s). d.

New Construction.

To fully realize the benefits of HFE, design must be influenced in the earliest phases of development.

Chapter 1 of enclosure (1) presents the basic design spiral, which is used in many segments of the maritime industry to depict the steps in planning the design of a new vessel.

At the first planning step of the design spiral, the Mission Requirements stage, HFE should be incorporated in the planning process by citing reference (a) as -a design criteria.

Reference (b) may be cited as a supplement to reference (a).

At each subsequent step in the design spiral, the man-machine interface should be evaluated to ensure the creation of a safe and efficient work environment.

A methodology for reviewing engineering design drawings for HFE considerations is provided in chapter 2 of enclosure (1). e.

Improvements To Existing Vessels.

Minor modifications such as changing equipment locations and operating control positions to improve human efficiency may not be cost effective on older ships.

HFE principles can be incrementally incorporated on a system- by-system basis during shipyard periods when system modernization, other major modifications, or maintenance/outfitting periods are scheduled, by using the pertinent sections of references (a) and (b) in the design specifications.

An area where immediate improvement in HFE can be achieved is the correction of deficient labeling.

This area offers the opportunity to produce the greatest increase in NAVIGATION AND VESSEL INSPECTION CIRCULAR NO. 4-89 safety on existing vessels for the least cost.

The extensive guidelines in reference (a) have been used to develop the information and examples in chapter 3 of enclosure (1). f.

Application to Coast Guard Marine Inspection and Casualty Investigation.

Marine inspectors can use HFE, while conducting inspections, to identify unsafe conditions.

If correction of HFE deficiencies cannot be required under present regulatory authority, the inspector will probably make appropriate recommendations to the Master, Chief Engineer, Port Engineer, etc. in a manner which will encourage the use of HFE principles.

Attention should be focused on the ship/system interface as a likely cause of accidents and reasons why a system fails to operate or does not operate as designed.

Investigating Officers can view all accidents from the HFE standpoint to see if there are any HFE related causal factors (contributing causes or precipitating causes, etc.).

The old standby cause, "error in judgment by ... in that he/she failed to ..." may be hiding poor design, fatigue, lack of training or skill, etc., which are the root causes of the operator error.

These root causes can be identified when an HFE perspective is used. g.

Reference Publications.

Although references (a) and (b) are definitive and authoritative sources of information on HFE, a wealth of additional information exists which can provide the reader with a deeper understanding of the discipline.

Chapter 4 of enclosure

(1) provides an abbreviated bibliography of HFE material.

Introduction to Human Factors Engineering — IMPLEMENTATION.

a. The Coast Guard welcomes industry comments from any source on the usefulness, adequacy, and applicability of this guide. Send comments to Commandant (G-MVI), United States Coast Guard, Washington, D.C., 20593-0001. b. Owners, operators, builders, and shipyard managers are encouraged to follow the guidelines provided in references (a) and (b) in planning modernization of older vessels and new construction. Vessel owners and shipyard Safety Engineers must be responsible for monitoring the accomplishment of HFE design and modification work. To perform this task they need to be familiar with the requirements of reference (a) and aware of the potential hazards of not adhering to its requirements. c. Vessel crews should take it upon themselves to identify and correct small HFE deficiencies such as labeling (marking), instruction manuals and minor rearrangement of spaces. Larger problems should be reported to company management for correction. d. It is recognized that some areas in present regulations conflict with HFE standards. Until these changes are made or policy is developed, regulatory requirements will continue to apply when there is a conflict. There will be many cases where HFE standards will dovetail with regulatory requirements (see the examples in chapter 3 of enclosure (1)). All interested parties are encouraged to advise Commandant (G-MVI) by letter, telephone, or other means when inconsistencies are discovered. e. It is further recognized that HFE guidance is limited with regard to commercial vessel casualty investigations. Commandant (G-MMI) is involved in R & D efforts focused on improving our ability to collect, store, process, analyze and apply human factors data concerning commercial vessel casualties. Results of these efforts are anticipated within a NAVIGATION AND VESSEL INSPECTION CIRCULAR NO. 4-89 year. Incorporation into policy will follow shortly thereafter. Until then, the HFE principles introduced in this Circular should be applied to commercial vessel casualty investigations as suggested in 3.f. End: (1) Guide for the Application of Human Factors Engineering to Commercial Vessels