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Frank and Lillian Gilbreth broke work into therbligs (elements).
The next step is to assign time values to the elements.
 Times for elements are added to obtain a total time.
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Independence and additivity are assumed.
PTS are based on the concept that there are basic, universal units of work with standard amounts of time.

 Developed in 1946
 Simplified versions are available.
 A training course is required for using the system correctly.

 10 categories of movements
 Times in TMUs (1 TMU = .000 010 h)
 Times are for an experienced worker working at a normal pave.
 No allowances are included in the times.

 Reach to an object in a fixed location or in the other hand.
 Reach to a single object whose general location is known.
 Reach to an object jumbled with others in a group.
 Reach to a very small object or where accurate grasp is required.
 Reach to an indefinite location.

 Move object to the other hand or against stop.
 Move object to an approximate or indefinite location.
 Move object to an exact location.

 A movement that rotates the hand, wrist, and forearm about the long axis of the forearm.
 Time depends on degrees of turn, weight of the object, and resistance against turn.

 Application of force without resultant movement.

 Pickup grasp
 Regrasp
 Transfer grasp
 Jumbled grasp
 Contact, sliding, or hook grasp

 Aligning, orienting, or engaging one object with another
 Position times vary with:
 Amount of pressure needed to fit
 Symmetry of the object
 Ease of handling

 Breaking contact between one object and another
 Times vary with:
 Class of fit
 Ease of handling
 Care in handling

 Relinquishing control of an object by the hand or fingers
 Two types:
 Simple opening of the fingers
 Contact release

 Body, leg, and foot motions
 Eye motions
 Combined motions
 Limited motions

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Takes about 40% of the time of MTM-1 to analyze a task.
Has only 37 times in all.
Key categories are GET and PUT.
Provides decision trees to determine case.
User estimates distance and uses time from table.
Includes 7 other motions.

 Takes about 15% of the time of MTM-1 to analyze a task.
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Has only 10 times.
Key categories are HANDLE and TRANSPORT.
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Provides decision trees to determine case.
User estimates distance (< 6 in. or > 6 in.) and uses time from table.
Includes 2 other motions.

 Based on observation that the majority of activities are associated with a limited number of motion sequences.
 Significantly reduces time required to perform an analysis.
 4 sequence models.

 Based on the concept that the body member used is the key variable.
 All body movements are multiples of a MOD (1
MOD = .129 s).

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In theory, PTS can accurately predict task times.
Evidence shows reality and theory don’t agree.
One problem is that analyst judgment is required.
Most managements are not concerned with a great deal of accuracy.
Managements are concerned with cost of analysis.

 Make a methods analysis to determine an efficient work method
 Determine the amount of time necessary to do the job