15.2 Single - Factor (One - Way) Analysis of Variance

Transcript 15.2 Single - Factor (One - Way) Analysis of Variance

Chapter 8 Human Resources in Operations Management

Human Resources In Strategic Planning

 Importance of employees  Education & training - long-term investments  Employees  broad latitude in jobs  trained in wide range of skills  empowered to improve quality & service

2000 by Prentice-Hall, Inc Ch 8 - 2 2

Evolution of Job Design

1900s to 1960s Scientific 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

2000 by Prentice-Hall, Inc Ch 8 - 6 3

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

2000 by Prentice-Hall, Inc Ch 8 - 7 4

Elements of Job Design

Worker Analysis Task Analysis Environmental Analysis

2000 by Prentice-Hall, Inc Ch 8 - 8 5

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

2000 by Prentice-Hall, Inc Ch 8 - 9 6

Worker Analysis

 Capability  Performance  Evaluation  Skill level  Physical  Mental stress  Boredom  Motivation  Number of workers  Level of responsibility  Monitoring level  Quality responsibility  Empowerment level

2000 by Prentice-Hall, Inc Ch 8 - 10 7

Environmental Analysis

 Work place location  Process location  Temperature and humidity  Lighting  Ventilation  Safety  Logistics  Space requirements  Noise  Vibration

2000 by Prentice-Hall, Inc Ch 8 - 11 8

Job Analysis

 Study how job should be done  Tools:  Process flowchart - analyze process steps  Worker-machine chart - study time utilization  Motion study - study human motions in tasks

2000 by Prentice-Hall, Inc Ch 8 - 12 9

Process Flowchart

Job: Page: Copying Job 1 Date: 9/11 Analyst: Calvin Desk operator fills out work order 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 Operator inspects job for irregularities Job filed alphabetically in completed shelves Job waits for pick up Job moved by cashier for pick up Cashier completes transaction Cashier packages job (bag, wrap, or box)

D D D D D D D D D D D D D D

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Job Photo-Id Cards Time -1 Operator -2 Worker-Machine Chart Date 10/14 Key in customer data on card Time 2.6

Photo Machine Idle -3 Feed data card in 0.4

Position customer for photo 1.0

Accept card Idle -4 Take picture 0.6

Begin photo process -5 -6 -7 Idle 3.4

Photo/card processed -8 -9 -10 Inspect card & trim edges 1.2

Idle

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Motion Study

 Frank & Lillian Gilbreth  Find one “best way” to do task  Divide task into therbligs  search, select, grasp, hold  Use videotape to study motions

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General Guidelines For Motion Study

 Efficient Use Of Human Body  Work - simplified, rhythmic & symmetric  Hand/arm motions - coordinated & simultaneous  Employ full extent of physical capabilities  Conserve energy - use machines, minimize distances, use momentum  Tasks - simple, minimal eye contact & muscular effort, no unnecessary motions, delays or idleness

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 Efficient Arrangement Of Workplace  Tools, material, equipment - designated, easily accessible location  Seating & work area - comfortable & healthy  Efficient Use Of Equipment  Equipment & mechanized tools enhance worker abilities  Use foot-operated equipment to relieve hand/arm stress  Construct & arrange equipment to fit worker use

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Work Measurement

 Estimate standard time required to perform a task  Methods of performing work measurement  Stopwatch time study  Elemental standard time files  Predetermined motion times  Work sampling

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Time Study Observation Sheet Identification of operation

Sandwich Assembly

Date Operator

Smith

Approval

Jones

Observer

Russell

1 2 3 4 Cycles 5 6 7 8 9 10



Summary

t RF Nt

1 2 3 4

Grasp and layout bread slices

.04 .05

.04 .38

.05 .04

.06 .05

.06

.06 .07 .05

.72 1.051.40 1.76 2.13 2.50 2.89 3.29

.53 .053 1.05 .056

Spread mayonnaise on both slices Place ham, cheese, and lettuce on bread

.07

.11

.12

.06 .07 .08

.07

.08

.10 .09

.08

.77 .077

1.00

.077

.44 .79 1.13 1.47 1.83 2.21 2.60 2.98 3.37

.11

.14 .12

.13

.12

.14

.14 1.28 1.28 1.10 .141

.23

.55

.93

1.25 1.60 1.96 2.34 2.72 3.12 3.51

.10

Place top on sandwich, slice and stack

.33

.12

.08 .09

.11

.10

.12

.10

1.03 1.03 1.10 .113

.67 1.01 1.34 1.71 2.07 2.44 2.82 3.24 3.61

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Stopwatch Time Study Basic Steps

1. 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 )

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6. Compute the normal time Normal Time = (Elemental average) (rating factor) Nt = ( t )(RF) Normal Cycle Time = NT =  Nt 7. Compute the standard time Standard Time = (normal cycle time) (1 + allowance factor) ST = (NT) (1 + AF)

2000 by Prentice-Hall, Inc

Incentive Piece-Rate Example

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

60 min min/ sandwich  or 135 sandwiches  Wage rate = (135)(0.04) = $5.40

2000 by Prentice-Hall, Inc

Number Of Cycles

n zs eT   2 where z  z value for desired confidence level s =   x i  x  2 n sample sta ndard deviation T = average job cycle time e = degree of error from true mean

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Number Of Cycles

 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 n zs eT   2 ) 0 05 0 361 )   2   11

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Work Sampling

 A technique for determining the proportion of time a worker or machine spend on various activities  Involves brief, random observations  Useful for non-repetitive tasks  E.g., secretary, nurse, police officer 2000 by Prentice-Hall, Inc 23

Work Sampling - Basic Steps

1. Define the job activities 2. Determine number of observations desired n z e   2 p  1  p  where n = sample size z  z value for desired confidence level e = degree of error from true mean p = proportion of time spent on activity prior to study

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3. Determine length of sampling period 4. Conduct work sampling study, record observations 5. Periodically re-compute number of observations

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Learning Curve

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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

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Learning Curve For Mass Production Job

Standard time End of improvement Units produced

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More On Learning Curves

 Not effective for mass production jobs  Little relative improvement, in a brief time span  Product modifications negate effects  Productivity improvement can derive from sources besides learning – such as?

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Computing Time For Nth Unit

t n = t 1 n b where     t n = time required for nth unit t 1 = time required for first unit n = cumulative number of units produced b = ln r/ln 2, where r is the percentage rate of improvement

2000 by Prentice-Hall, Inc

15.2 Single - Factor (One - Way) Analysis of Variance

Transcript 15.2 Single - Factor (One - Way) Analysis of Variance

Chapter 8 Human Resources in Operations Management

Human Resources In Strategic Planning

Evolution of Job Design

Evolution Of Job Design

Elements of Job Design

Task Analysis

Worker Analysis

Environmental Analysis

Job Analysis

Motion Study

General Guidelines For Motion Study

Work Measurement

Stopwatch Time Study Basic Steps

Incentive Piece-Rate Example

Number Of Cycles

Number Of Cycles

Work Sampling

Work Sampling - Basic Steps

Learning Curve

Learning Curve

Learning Curve For Mass Production Job

More On Learning Curves

Computing Time For Nth Unit

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