Process Analysis, Job Design, and Work Measurement

1
Process Analysis, Job Design, and Work Measurement

• Selected Slides from Jacobs et al, 9th Edition
• Operations and Supply Management
• Chapter 6 and 6A
• Edited, Annotated and Supplemented by
• Peter Jurkat

2
Process Analysis Terms
6-2

• Process Is any part of an organization that
  takes inputs and transforms them into outputs
• Cycle Time Is the average successive time
  between completions of successive units
• Utilization Is the ratio of the time that a
  resource is actually activated relative to the
  time that it is available for use

3
Process FlowchartingDefined
6-3

• Process flowcharting is the use of a diagram to
  present the major elements of a process
• The basic elements can include tasks or
  operations, flows of materials or customers,
  decision points, and storage areas or queues
• It is an ideal methodology by which to begin
  analyzing a process

4
6-4
Flowchart Symbols
Purpose and Examples
Examples Giving an admission ticket to a
customer, installing a engine in a car, etc.
Examples How much change should be given to a
customer, which wrench should be used, etc.
5
6-5
Flowchart Symbols
Purpose and Examples
Examples Sheds, lines of people waiting for a
service, etc.
Examples Customers moving to a seat, mechanic
getting a tool, etc.
6
Process Flowcharting
6-6

• Process flowcharting is the use of a diagram to
  present the major elements of a process
• The basic elements can include tasks or
  operations, flows of materials or customers,
  decision points, and storage areas or queues
• It is an ideal methodology by which to begin
  analyzing a process

7
6-7
8
6-8
Process Architecture
push
pull
9
In-process-inventory
6-9

• A buffer refers to a storage area (in-process
  inventory) between stages where the output of a
  stage is placed prior to being used in a
  downstream stage

10
6-10
Step 1 ? Buffer ? Step 2 Example
Now you/we do 6.8
11
Other Process Terminology
6-11

• Blocking
• Occurs when the activities in a stage must stop
  because there is no place to deposit the item
  just completed
• If there is no room for an employee to place a
  unit of work down, the employee will hold on to
  it not able to continue working on the next unit
• Fix with buffer?
• Starving
• Occurs when the activities in a stage must stop
  because there is no work
• If an employee is waiting at a work station and
  no work is coming to the employee to process, the
  employee will remain idle until the next unit of
  work comes
• Fix with pull system?

12
Other Process Terminology (Continued)
6-12

• Bottleneck
• Occurs when the limited capacity of a process
  causes work to pile up or become unevenly
  distributed in the flow of a process
• If an employee works too slow in a multi-stage
  process, work will begin to pile up in front of
  that employee. In this is case the employee
  represents the limited capacity causing the
  bottleneck.
• Pacing
• Refers to the fixed timing of the movement of
  items through the process

Now you do 6.9
13
Other Types of Processes
6-13

• Make-to-order (pull)
• Only activated in response to an actual order
• Both work-in-process and finished goods inventory
  kept to a minimum
• Make-to-stock (push)
• Process activated to meet expected or forecast
  demand
• Customer orders are served from target stocking
  level

14
6-14
Measuring Process Performance
Throughput time can also be estimated by Littles
Law (time) Work-in-process inventory (units)
/throughput rate (units/time) Now you do 6.10
15
Cycle Time Example
6-15

• Suppose you had to produce 600 units in 80 hours
  to meet the demand requirements of a product.
  What is the cycle time to meet this demand
  requirement?

Answer There are 4,800 minutes (60 minutes/hour
x 80 hours) in 80 hours. So the average time
between completions would have to be Cycle time
4,800/600 units 8 minutes.
Now you do 6.4 and 6.5
16
What is Job Design?Defined
6A-16

• Job design is the function of specifying the work
  activities of an individual or group in an
  organizational setting
• The objective of job design is to develop jobs
  that meet the requirements of the organization
  and its technology and that satisfy the
  jobholders personal and individual requirements

17
Job Design Decisions
6A-17
18
Trends in Job Design

• Quality control as part of the worker's job
• Cross-training workers to perform multi -skilled
  jobs
• Employee involvement and team approaches to
  designing and organizing work
• "Informating sic ordinary workers through
  e-mail and the Internet

• Extensive use of temporary workers
• Automation of heavy manual work
• Creating alternative workplaces
• Shared offices
• Tele-commuting
• Virtual offices
• Organizational commitment to providing
  meaningful and rewarding jobs for all employees

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Physical Considerations in Job Design
6A-19

• Work physiology sets work-rest cycles according
  to the energy expended in various parts of the
  job. The harder the work, the more the need for
  rest periods.
• Ergonomics is a term used to describe the study
  of the physical arrangement of the work space
  together with tools used to perform a task. Fit
  the work to the body rather than forcing the body
  to conform to the work.

20
Work Measurement Defined
6A-20

• Work measurement is a process of analyzing
  jobs for the purpose of setting time
  standards
• Why use it?
• Schedule work and allocate capacity
• Motivate and measure work performance
• Evaluate performance
• Provide benchmarks

21
Time Study Normal Time Formulas
6A-21

• Normal time(NT)Observed performance time per
  unit x (Performance rating)
• The Performance Rating is usually expressed in
  decimal form in these formulas. So a person
  working 10 faster than normal would have a
  Performance Rating of 1.10 or 110 of normal
  time. Working 10 slower, 0.90 or 90 of normal.
• NT Time worked _ x
  (Performance rating) Number of units
  produced

22
Time Study Standard Time Formulas
6A-22

• Standard time Normal time (Allowances x
  Normal times)
• Allowances add time for breaks, fatigue,
  equipment maintenance and/or failure
• Standard time NT(1 Allowances)
• Standard time NT .
• 1 - Allowances

23
Time Study Example Problem
6A-23

• The employee produced 20 units of product in an 8
  hour day.
• Your observations made the employee nervous -
  estimate employee worked 10 percent faster than
  normal.
• Allowances for the job represent 25 percent of
  the normal time.
• Question What are the normal and standard times
  for this job?

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Time Study Example Solution
6A-24

• Normal time Time worked
  x (Perf. rating) Number of
  units produced
• (480 minutes/20) x (1.10)
• 26.4 minutes
• Standard time NT .
• 1 Allowances
• (26.4)/(1-0.25)
• 35.2 minutes

25
6A-25
26
Work Sampling
6A-26

• Time studies make workers nervous often
  restricted by unions
• Better to use inference to make statements about
  work activity based on a sample of the activity
  use statistical methods (select confidence,
  calculate sample size, observe, analyze)
• Ratio Delay
• Activity time percentage for workers or equipment
  (portion of time work is actually done value
  added)
• Performance Measurement
• Relates work time to output (performance index)
• Time Standards
• Standard task times

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Advantage of Work Sampling over Time Study

• Several work sampling studies may be conducted
  simultaneously by one observer
• The observer need not be a trained analyst unless
  the purpose of the study is to determine a time
  standard
• No timing devices are required
• Work of a long cycle time may be studied with
  fewer observer hours

• The duration of the study is longer, which
  minimizes effects of short-period variations
• The study may be temporarily delayed at any time
  with little effect
• Because work sampling needs only instantaneous
  observations (made over a longer period), the
  operator has less chance to influence the
  findings by changing work method