© 2000 by Prentice-Hall Inc Russell/Taylor Oper Mgt 3/e Chapter 8 Human Resources in Operations Management

© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e

Chapter 8

Human Resources in Operations Management

2000 by Prentice-Hall, Inc 2Ch 8 - 2© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e

Human Resources In Strategic Planning

Importance of employeesEducation & training - long-term

investmentsEmployees

broad latitude in jobstrained in wide range of skillsempowered to improve quality & service


Evolution of Job Design 1900s to 1960sScientific Management/Assembly Lines

Task specialization Minimal worker

skills Repetition Minimal job training Mass production

Piece-rate wages Time as efficiency Minimal job

responsibility Tight supervisory

control


Evolution Of Job Design 1970s to 1990s

Horizontal job enlargement

Vertical job enlargement

Extensive job training

Job responsibility & empowerment

Job control

Training & education Job rotation Higher skill levels Team problem

solving Employee

involvement & interaction

Focus on quality


Elements of Job Design

Task AnalysisWorker Analysis

Environmental Analysis


Task Analysis

Description of tasks Task sequence Function of tasks Frequency of tasks Criticality of tasks Relationship with

other jobs/tasks

Performance requirements Information requirements Control requirements Error possibilities Task duration(s) Equipment requirements


Worker Analysis

Capability Performance Evaluation Skill level Physical Mental stress Boredom

Motivation Number of workers Level of

responsibility Monitoring level Quality responsibility Empowerment level


Environmental Analysis

Work place location Process location Temperature and

humidity Lighting Ventilation

Safety Logistics Space requirements Noise Vibration


Job AnalysisStudy how job should be done

Tools:

Process flowchart - analyze process steps

Worker-machine chart - study time utilization

Motion study - study human motions in tasks


Desk operator fills out work order

Date: 9/11

Analyst: Calvin

Job: Copying Job

Work order placed in “waiting job” box

Job picked up by operator and read

Job carried to appropriate copy machine

Operator waits for machine to vacate

Operator loads paper

Operator sets machine

Operator performs and completes job

Job filed alphabetically in completed shelves

Job waits for pick up

Job moved by cashier for pick up

Cashier completes transaction

Operator inspects job for irregularities

Cashier packages job (bag, wrap, or box)

Page: 1

D

DDDD

DDDDD

DD

D

D

Process Flowchart


Worker-Machine Chart

Job Photo-Id Cards Date 10/14

Time Operator Time Photo Machine

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

Key in customer data on card

Feed data card in

Position customer for photo

Take picture

Inspect card & trim edges

Idle

Idle

Idle

Idle

Photo/card processed

Accept card

Begin photo process

2.6

0.4

1.0

0.6

3.4

1.2


Motion Study

Frank & Lillian GilbrethFind one “best way” to do taskDivide task into therbligs

search, select, grasp, holdUse videotape to study motions


General Guidelines For Motion Study

Efficient Use Of Human BodyWork - simplified, rhythmic & symmetricHand/arm motions - coordinated & simultaneousEmploy full extent of physical capabilitiesConserve energy - use machines, minimize

distances, use momentumTasks - simple, minimal eye contact & muscular

effort, no unnecessary motions, delays or idleness


Efficient Arrangement Of WorkplaceTools, material, equipment - designated, easily

accessible locationSeating & work area - comfortable & healthy

Efficient Use Of EquipmentEquipment & mechanized tools enhance worker

abilitiesUse foot-operated equipment to relieve hand/arm

stressConstruct & arrange equipment to fit worker use


Work Measurement

Estimate standard time required to perform a task

Methods of performing work measurement

Stopwatch time studyElemental standard time filesPredetermined motion timesWork sampling


1 2 3 4 5 6 7 8 9 10 t t NtRF

Time Study Observation Sheet

t

t

t

t

R

R

R

R

Place top on sandwich,slice and stack

Place ham, cheese, and lettuce on bread

Spread mayonnaiseon both slices

Grasp and layoutbread slices1

2

3

4

Identification of operation Sandwich Assembly

Operator Approval Observer

Smith Jones Russell

Cycles Summary

Date

.04 .05 .05 .04 .06 .05 .06 .06 .07 .05 .53 .053 1.05 .056

.04 .38 .72 1.051.40 1.76 2.13 2.50 2.89 3.29

.07 .06 .07 .08 .08 .08.07 .07 .10 .09

.11 .44 .79 1.13 1.47 1.83 2.21 2.60 2.98 3.37

.77 .077 .0771.00

.11.12 .14 .12 .12.13.13.13 .14 .14 1.28 1.28 1.10 .141

.93.23 .55 1.25 1.60 1.96 2.34 2.72 3.12 3.51

.12.10 .08 .09 .12 .10.11 .11 .10.10 1.03 1.03 1.10 .113

.33 .67 1.011.34 1.712.07 2.44 2.82 3.24 3.61


Stopwatch Time Study Basic Steps1. Establish the standard job method

2. Break down the job into elements

3. Study the job

4. Rate the worker’s performance (RF)

5. Compute the average time ( t )


6. Compute the normal timeNormal Time = (Elemental average) (rating factor)

Nt = ( t )(RF)

Normal Cycle Time = NT = Nt

7. Compute the standard timeStandard Time = (normal cycle time) (1 + allowance

factor)

ST = (NT) (1 + AF)


Incentive Piece-Rate Example

Piece-rate is $0.04 per sandwich What would average worker earn per hour?

Wage rate = (135)(0.04) = $5.40

600 445

134 8 135min

. min/.

sandwichor sandwiches


Number Of Cycles

nzseT

where

z

ix xn sample sta

2

2

1

z value for desired confidence level

s = ndard deviation

T = average job cycle time

e = degree of error from true mean


Number Of Cycles

nzseT

2 2

196 0 030 05 0 361

10 61 11( . )( . )

( . )( . ).

Average cycle time (without Rating Factor) =0.361

Computed standard deviation = 0.03 Company wants to be 95% confident that

computed time is within 5% of true average time

2000 by Prentice-Hall, Inc 23

Work SamplingA technique for determining the

proportion of time a worker or machine spend on various activities

Involves brief, random observationsUseful for non-repetitive tasksE.g., secretary, nurse, police officer


Work Sampling - Basic Steps

1. Define the job activities

2. Determine number of observations desired

nze

p p

z

2

1

where

n = sample size

z value for desired confidence level

e = degree of error from true mean

p = proportion of time spent on activity prior to study


3. Determine length of sampling period

4. Conduct work sampling study, record observations

5. Periodically re-compute number of observations


Learning Curve

Pro

cess

ing

time

per

unit

Units produced


Learning Curve

Processing time decreases with worker learning (experience)

Time per unit decreases by constant percentage each time output doubles

Useful for nonrepetitive, complex jobs requiring requiring long time to complete


Learning Curve For Mass Production Job

Standard time

End of improvementPro

cess

ing

time

per

unit

Units produced


More On Learning Curves

Not effective for mass production jobsLittle relative improvement, in a brief

time spanProduct modifications negate effectsProductivity improvement can derive

from sources besides learning – such as?


Computing Time For Nth Unit

tn = t1nb

where tn = time required for nth unit

t1 = time required for first unit n = cumulative number of units

produced b = ln r/ln 2, where r is the percentage

rate of improvement

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© 2000 by Prentice-Hall Inc Russell/Taylor Oper Mgt 3/e Chapter 8 Human Resources in Operations Management