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Predetermined Time Systems

IENG 311

Work MethodsCarter J. Kerk, PhD, PE, CSP, CPE

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Predetermined Time Systems

PDTS

Read Chapter 29 from Konz & Johnson, 6th

Edition

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Objectives - PDTS

Describe the general concept of PDTS

Understand the difference between PDTS

and other standard data systems Understand the procedure for calculating a

time standard with PDTS

Know the advantages and disadvantages ofusing a PDTS for setting time standards

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Introduction

There are times when it is not possible or

practical to set time standards using time

study.

You may want to use Standard Data

(Chapter 30) or Pre-Determined Time

Systems (This chapter!)

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Therbligs

Frank and Lillian Gilbreth took a detailedlook at work and broke work into 17 micro-elements, called Therbligs

They used Therblig analysis to performmicromotion analysis of tasks (yes, they didthis in the early part of the 1900s)

They used it to analyze bricklaying (a 2000year-old task) and were able to increaseproductivity by 300%

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Therbligs

G Grasp

P Position

PP Pre-position

U Use

A Assemble

DA Disassemble

RL Release Load

TE Transport Empty

TL Transport Loaded

SH Search

ST Select

H Hold

UD Unavoidable Delay

AD Avoidable Delay

R Rest

PN Plan

I Inspect

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The Concept of PDTS

Take basic, fundamental, universal units of

work

Attach standard amounts of time MTMMethods Time Measurement

MOST (Maynard Operational Sequence

Technique) MODAPTS

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MTM

MTM-1: Basic and most detailed version

250 times the cycle time to analyze the task

Simplified Versions of MTM (less accurate) MTM-2: 100 times the cycle time to analyze the

task

MTM-3: 35 times the cycle time to analyze the

task

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MTM - 1

Motions are broken into 20 categories

Reach, Move, Turn, Apply Pressure, Grasp,Position, Release, Disengage, Body Motions

(leg-foot, horizontal, vertical), Eye Motions Times for each motion is given in TMUs

(see next slide)

Times are for experienced operatorsworking at a normal pace (100%)

No allowances are included

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MOST

Maynard Operational Sequence Technique

Developed in Sweden by Zandin

The vast majority of activities involved withthe handling of an object were associatedwith a limited number of motion sequences

By taking advantage of this point, the time

required to perform an analysis issignificantly reduced from that required byMTM without a reduction in precision.

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MOST

Four Sequence Models

General Move, Controlled Move, Tool Use,Manual Crane

MiniMOST for short-cycle, highly repetitive operations

This system requires more time

MaxiMOST For long-cycle times, with many non-identical

operations

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MOST

Basic MOST

General Move Sequence

Three components: Get, Put, Return

Example

GET: A1 B0 G1

PUT: A1 B0 P3

RETURN: A1

See next slide for General Move Model

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What is a TMU?

TMU: Time Measurement Unit

1 hour = 100,000 TMU

1 minute = 1667 TMU 1 second = 27.78 TMU

0.00001 hour

0.0006 minutes 0.036 seconds