Allocating Tasks To People and Machines

What should machines do?

What should people do?

These are important decisions in the design of any workstation, manufacturing system or process. Such decisions affect product quality, flexibility, overhead cost, worker health and the economic viability of the process. 

The list below shows some of the relevant factors for making such decisions.

An Over-Automation Example

In the early days of of the Mercury space program, NASA engineers attempted to automate almost every aspect of space flight. The original Mercury 7 astronauts vehemently objected to their proposed role as mere passengers. They called it "Spam In A Can." As a result, Mercury and subsequent manned spacecraft designs assigned significant roles and tasks to the astronauts. The unique value that humans bring to certain tasks was demonstrated dramatically with the Apollo 13 mission. 

This is an example of the strong tendency in some organizations to "over-automate" and assign most tasks to machines. However, insufficient automation is equally ineffective. Much depends on the state of the technology and the relative economics of automation and labor.

What People Are Good At

• Nebulous Information

• Subtle Decisions

• Vague Process Definitions

• Interactions With Other People

• High Variety

• Short Runs

• Varied Cycle Times

• Quick Changeover

• Varied Inputs

• Multiple Work Locations

What Machines & Computers Are Good At

• Simple, Quantitative & Accurate Information

• Simple, Straight-Forward Decisions

• Sharply Defined Processes

• No Customer Interfaces

• Repetition

• Short Cycle times

• Long Runs

• High Volume

• High Precision

• Heavy Loads/Large Forces

Ergonomic Series Articles

Ergonomics In Lean Manufacturing

Physiology
Biomechanics In Workstation Design
Anthropometry
Man-Machine Allocation
Musculoskeletal Disorders
Principles of Ergonomics
Ergo Download

References

ANSI/HFES100-1988, Human Factors & Ergonomic Society, 1988.

Eastman Kodak Company, Ergonomic Design for People at Work, Van NostrandReinhold, New York, 1986.

Fraser, M., the Worker At Work, Taylor & Francis, New York, 1989.

Lee, Q, Nelson W., Amundsen, A., &  Tuttle, H., Facilities and Workplace Design, Institute of Industrial Engineers, Atlanta, Georgia, 1996.

Woodson, Wesley E. and Conover, Donald W., Human Engineering for Equipment Design 2nd Rev. Edition, University of California Press, Berkely, 1966.

Zandin, Kjell B. and Maynard, Harold B., Industrial Engineering Handbook 5TH Edition, McGraw-Hill, New York, 2001.