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.
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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.
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
Your turn …
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
Comments about PTS
In theory, PTS can accurately predict task times. Evidence shows reality and theory don’t agree.
One problem is that analyst judgment is required. For the most part, consistency and cost are
more important than accuracy. a consistent deviation from reality can be adjusted for
Purpose of a PTS study use methods analysis to determine an efficient work
method determine the amount of time necessary to do the job