Predetermined Time SystemsPredetermined Time Systems

BYBY

MEGHANT NICHANTMEGHANT NICHANT

INDUSTRIAL ENGINEERINDUSTRIAL ENGINEER

Predetermined Time SystemsPredetermined Time Systems

PDTSPDTS Read Chapter 29 from Konz & Johnson, 6Read Chapter 29 from Konz & Johnson, 6thth

EditionEdition

Objectives - PDTSObjectives - PDTS

Describe the general concept of PDTSDescribe the general concept of PDTS Understand the difference between PDTS Understand the difference between PDTS

and other standard data systemsand other standard data systems Understand the procedure for calculating a Understand the procedure for calculating a

time standard with PDTStime standard with PDTS Know the advantages and disadvantages of Know the advantages and disadvantages of

using a PDTS for setting time standardsusing a PDTS for setting time standards

IntroductionIntroduction

There are times when it is not possible or There are times when it is not possible or practical to set time standards using time practical to set time standards using time study.study.

You may want to use Standard Data You may want to use Standard Data (Chapter 30) or Pre-Determined Time (Chapter 30) or Pre-Determined Time Systems (This chapter!)Systems (This chapter!)

TherbligsTherbligs

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

They used Therblig analysis to perform They used Therblig analysis to perform micromotion analysis of tasks (yes, they did micromotion analysis of tasks (yes, they did this in the early part of the 1900s)this in the early part of the 1900s)

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

TherbligsTherbligs GG GraspGrasp PP PositionPosition PPPP Pre-positionPre-position UU UseUse AA AssembleAssemble DADA DisassembleDisassemble RLRL Release LoadRelease Load TETE Transport EmptyTransport Empty TLTL Transport LoadedTransport Loaded

SHSH SearchSearch STST SelectSelect HH HoldHold UDUD Unavoidable Unavoidable

DelayDelay ADAD Avoidable DelayAvoidable Delay RR RestRest PNPN PlanPlan II InspectInspect

The Concept of PDTSThe Concept of PDTS

Take basic, fundamental, universal units of Take basic, fundamental, universal units of workwork

Attach standard amounts of timeAttach standard amounts of time MTM – Methods Time MeasurementMTM – Methods Time Measurement MOST (Maynard Operational Sequence MOST (Maynard Operational Sequence

Technique)Technique) MODAPTSMODAPTS

MTMMTM

MTM-1: Basic and most detailed versionMTM-1: Basic and most detailed version– 250 times the cycle time to analyze the task250 times the cycle time to analyze the task

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

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

task task

MTM - 1MTM - 1

Motions are broken into 20 categoriesMotions are broken into 20 categories– Reach, Move, Turn, Apply Pressure, Grasp, Reach, Move, Turn, Apply Pressure, Grasp,

Position, Release, Disengage, Body Motions Position, Release, Disengage, Body Motions (leg-foot, horizontal, vertical), Eye Motions(leg-foot, horizontal, vertical), Eye Motions

Times for each motion is given in “TMUs” Times for each motion is given in “TMUs” (see next slide)(see next slide)

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

No allowances are includedNo allowances are included

MOSTMOST

Maynard Operational Sequence TechniqueMaynard Operational Sequence Technique Developed in Sweden by ZandinDeveloped in Sweden by Zandin The vast majority of activities involved with The vast majority of activities involved with

the handling of an object were associated the handling of an object were associated with a limited number of motion sequenceswith a limited number of motion sequences

By taking advantage of this point, the time By taking advantage of this point, the time required to perform an analysis is required to perform an analysis is significantly reduced from that required by significantly reduced from that required by MTM without a reduction in precision.MTM without a reduction in precision.

MOSTMOST

Four Sequence ModelsFour Sequence Models– General Move, Controlled Move, Tool Use, General Move, Controlled Move, Tool Use,

Manual CraneManual Crane MiniMOSTMiniMOST

– for short-cycle, highly repetitive operationsfor short-cycle, highly repetitive operations– This system requires more timeThis system requires more time

MaxiMOSTMaxiMOST– For long-cycle times, with many non-identical For long-cycle times, with many non-identical

operationsoperations

MOSTMOST

Basic MOSTBasic MOST– General Move SequenceGeneral Move Sequence

Three components: Get, Put, ReturnThree components: Get, Put, Return ExampleExample

– GET: A1 B0 G1GET: A1 B0 G1– PUT: A1 B0 P3PUT: A1 B0 P3– RETURN: A1RETURN: A1

– See next slide for General Move ModelSee next slide for General Move Model

What is a TMU?What is a TMU?

TMU: Time Measurement UnitTMU: Time Measurement Unit 1 hour = 100,000 TMU1 hour = 100,000 TMU

– 1 minute = 1667 TMU1 minute = 1667 TMU– 1 second = 27.78 TMU1 second = 27.78 TMU

0.00001 hour0.00001 hour– 0.0006 minutes0.0006 minutes– 0.036 seconds0.036 seconds