1 ISE 311 - 24 Ch. 26: Predetermined Time Systems 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. Independence and additivity are assumed. PTS are based on the concept that there are basic, universal units of work with standard amounts of time.
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# 1 ISE 311 - 24 Ch. 26: Predetermined Time Systems Frank and Lillian Gilbreth broke work into therbligs (elements). The next step is to assign time values.

Dec 17, 2015

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1ISE 311 - 24

Ch. 26: Predetermined Time Systems

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. Independence and additivity are assumed.

PTS are based on the concept that there are basic, universal units of work with standard amounts of time.

2ISE 311 - 24

Therbligs

The smallest unit of activity in a task.

“Gilbreth” backward (sort of)

from: http://gilbrethnetwork.tripod.com/therbligs.html#Chart

3ISE 311 - 24

Methods-Time Measurements (MTM)

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

system correctly.

4ISE 311 - 24

MTM-1 10 categories of movements Times in TMUs (1 TMU = .000 010 h) Times are for an experienced worker working at

a normal pace. No allowances are included in the times.

5ISE 311 - 24

Reach (table 26.1, pg. 503)

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.

6ISE 311 - 24

Move (table 26.2, pg. 504)

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

location. Move object to an exact location.

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Turn (table 26.4, pg. 506)

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.

Apply Pressure (table 26.5, pg. 506)

Application of force without resultant movement.

8ISE 311 - 24

Grasp (table 29.6, pg. 567)

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

9ISE 311 - 24

Position (table 26.7, pg. 508)

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

10ISE 311 - 24

Disengage (table 26.8, pg. 509)

Breaking contact between one object and another

Times vary with: Class of fit Ease of handling Care in handling

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Release (table 26.9, pg. 509)

Relinquishing control of an object by the hand or fingers

Two types: Simple opening of the fingers Contact release

12ISE 311 - 24

Other Motions

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

13ISE 311 - 24

MTM Form

14ISE 311 - 24

MTM-2

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.

15ISE 311 - 24

MTM-2 Analysis

16ISE 311 - 24

MTM-3

Takes about 15% of the time of MTM-1 to analyze a task.

Has only 10 times. Key categories are HANDLE and TRANSPORT. Provides decision trees to determine case. User estimates distance (< 6 in. or > 6 in.) and

uses time from table. Includes 2 other motions.

17ISE 311 - 24

MTM-3 Analysis

18ISE 311 - 24

MOST Work Measurement System

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 (pp. 513 – 516) General move sequence [A B G A B P A] Controlled move sequence [A B G M X I A] Tool use sequence [A B G A B P use* A B P A] Manual crane sequence [A B G M X I A, specific to

crane use.]

19ISE 311 - 24

General Move Sequence Model

20ISE 311 - 24

Perform a MOST analysis of the peg board task.

Perform a MOST analysis of writing “MOST” on your notes with a pencil (assume the pencil is picked up from the desk at the beginning and returned to the desk at the end of the task.)

21ISE 311 - 24

MODAPTS

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).

22ISE 311 - 24