The rough edges between the components in the SHEL diagram are symbolic of the fact that the mismatch between an individual and these components is important. These possible mismatches warrant special attention by the marine investigator because mismatches in the system may point out safety deficiencies. Examples of mismatches between a person and other components include:

　

□ Person to Person (liveware-liveware) Mismatches. Mismatches between people and other people include voice communications, working language, phraseology, speech rate, readback/hearback, briefings, personal interactions, crew coordination, and non-verbal ques such as hand signals.

□ Person to Policy & Procedures (liveware-software) Mismatches:

Mismatches between liveware and software include problems in the transfer of information between support systems and the person. Outdated publications, for instance, generate a mismatch by giving the person incorrect information.

□ Person to Equipment & Gear (liveware-hardware) Mismatches:

Mismatches between liveware and hardware include problems in the physical and mental interaction of people and machines. Design limitations, instrument/control design and location, instrument controls and readability, seat design, proper guards and protections and other ergonomic issues are instances of these mismatches.

□ Person to Environment (liveware-environment) Mismatches.

Mismatches between people and environment are facts that affect human performance. For example temperature, humidity, illumination or glare, ambient noise, vibration, air quality, external visibility, pitch and yaw each have an effect on a person s ability to perform his or her task optimally.

　

The lists below contain the various areas of examination of mismatches. The lists are not exhaustive.

　

Oral Communication. Tapes and witness interviews can help identify misinterpretations, misunderstandings, and improper language use. Consider:

Crew Interaction. Crew interaction includes crew compatibility in terms of personality, experience level, and working habits. These factors can cause people to work for or against each other, or fail to use all available resources.

Passenger Interaction. Like crew interactions, passenger interaction occasionally influences the performance of individuals. Passengers can provide information on crew actions, attitudes, and behaviors.

Worker - Management Factors. Consider:

Labor Relations. Labor relations include, for instance, union influence on workers, management, policies, and work habits; post-merger negotiations, etc.

Pressures. Pressures may include real or perceived mental pressure due to operational policies, fellow Workers, management, turnover, etc.

Supervision Factors. Supervision factors include the existence, availability, and currency of standards, policies, and quality controls, as well as supervisory presence (or absence), monitoring, style, etc.

Regulatory Requirements. This factor relates to the person-to-person importance placed on regulatory compliance. Consider factors such as the operating culture, which may encourage "bending" of the rules or place little value on compliance.

　

Written Information. Consider the format, content, and/or vocabulary of manuals, checklists, or any other written documents.

Computers. Consider the compatibility of keyboards or displays, their impact on workload, and inducement of confusion, increased reaction time, task fixation, or blatant errors.

Automation. Consider the effect of automated equipment or procedures on a person's attitude toward their work, mental picture of the mission, an impact on workload at a critical time.

Regulatory Requirements. Consider the individual's essential qualifications and certifications for the task, e.g. current licenses or ratings, qualifications for equipment type, infraction history, etc.

　

Switches, Controls, and Displays. Similarities, differences, and peculiarities between different systems' switches, controls, and displays may affect an individual's information processing characteristics. Consider:

Workspace Factors. Consider:

　

Internal Environment. Consider the climate, personal comfort, workplace environment and physical working conditions.

Marine Environment. Consider the weather, sea state, tides, currents, visibility conditions, precipitation, and rate of change in weather conditions.

Infrastructure. Consider the infrastructure or support services and their contribution toward reducing safety margins, or limiting choices of action, maintenance being one of the key facilities affecting an occurrence.