Human Factors Engineering

Presented by:A. C. Macris

A. C. Macris Consultants

Here’s a group of seemingly unrelated things

The Common Thread

The common thread is –

People

An academic definition of Human Factors Engineering

The central focus of human factors relates to the consideration of human beings in the design of man-made objects, facilities and environment that people “use” in the various aspects of their lives.

The central approach is the systematic application of relevant information about human characteristics and behavior to the design of the these objects, facilities and environments.

Design

Design of:• Products• Systems• Environments

Why is design so important?

Design

• Is proactive• Is driven by a need or requirement• Can cost more initially, but

Good human factors design yields returns in improved performance and

reliability.

DesignLet us look at a simple example of

design

This is a rather conventional American design

Design

This car was imported into the US in the late 1970s from Italy. Note the Tachometer in the center with the Speedometer to the

right along with more instrumentation. The cultural design difference is there were no speed limits in Italy, but engine speed was of considerable interest. Needless to say this design did not

last long in the US.

Design considerations

• Safety • Environment [hostile such as outer-space,

deep sea]• Population [age/geriatric, physical

characteristics, etc.]• Compatible work environments [lighting,

color, temperature, etc.]• Task to be accomplished• Culture• Efficient processes and workflows• Right people in the right job

Assessment

Assessment of:• Products• Systems• Environments

Assessment

Typically is in response to something gone wrong– Products - equipment– Systems - warnings– Environment - hazards

Can be proactive in the context of– Prevent injury

Assessment yields returns in the context of avoiding future losses, better design and

improved operations.

ProductsTable Saw Blade Guarding

Guard Design

Design issues with guard

Red line indicates a plastic piece across inner part of guard – sawdust collects making visibility difficult

Dimension of guard width and ability to rip narrow pieces of wood

Setup and alignment is tedious

Alternative

A page from a newer saw – they afforded the user an alternative for

narrow ripping cuts.

No Guard

Table Saw Guarding SurveyWe conducted a very comprehensive Table Saw guarding survey. Below is a summary of the findings.

Four reasons sited for not using guardDifficult to adjustGets in the waySafer without itInhibits my work

One reason not sited for not using a guardTakes longer to cut

Reason that they would more apt to use a guardBetter design and loss of fingers was the reason respondents gave.

Better Guard Design

• Safer = fewer legal actions• Marketing advantage = competitive

advantage• More sales for commercial users

Systems - Warnings

Warnings represent a broad range of human interface issues. These issues include:

– Effectiveness of warnings, – Whether warnings actually affect

behavior, – Which types of warnings are most

effective, – With which types of products are

warnings most likely to be heeded

Systems - Warnings

1. Warnings must be provided if, without such warnings, the product would be unreasonably dangerous.

2. The ultimate users of the product, or those individuals, who might be expected to be proximate to the use of the product, are the ones to whom the warnings should be directed.

Systems - Warnings

For a warning to be effective the user must:

• Notice the warning (color, design, etc)

• Perceive the warning (low voltage v. high voltage)

• Understand the warning (convey the right message)

Design of WarningsProduct Safety Sign or Label: Sign, label, or decal affixed to a product that provides hazard and safety information about that product.Panel: Area of label having a distinctive background color different from adjacent areas, or which is clearly delineated by a line, border, or margin. Message Panel: Area containing word messages which identify the hazard, how to avoid the hazard, and the probable consequence of not avoiding the hazard.Signal Word Panel: Area that contains the signal word. For personal injury hazards, the signal word panel also contains the safety alert symbol.Symbol/Pictorial Panel: Optional area containing symbol/pictorial.

Design of Warnings

Conventionsan imminently hazardous situation which, if not avoided, will result in death or serious injury a potentially hazardous situation which, if not avoided, could result in death or serious injury a potentially hazardous situation which, if not avoided, may result in minor or moderate injury

Thank you Contact information:A. C. Macris Consultants

PO Box 535

Mystic, Connecticut 06355

860.572.0043

acmpc@acmacris.com