DAVIS
F O U R T H
E D I T I O N
AQUILANO
CHASE
supplement 10
Work Performance
Measurement
© The McGraw-Hill Companies, Inc., 2003
PowerPoint
Presentation
by
Charlie
Cook
Supplement Objectives
• Introduce the more common types of work methods
that are practiced in the workplace.
• Understand the fundamental issues involved in
developing work measurements.
• Identify the basic elements associated with conducting
a time study.
• Determine how to design a work sampling study and
apply it to an actual operation.
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
S10–2
Work Methods
• Studying the production system to:
–Identify non-valued-added time delays, transport
distances, process and processing time
requirements
–Simplify the entire operation by eliminating any
step that does not add value to the product.
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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Work Methods and Design Aids
Exhibit S10.1
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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Flow Diagram and Process Chart of an Office
Procedure—Present Method*
*Requisition is written by supervisor, typed by secretary, approved by superintendent,
and approved by purchasing agent; then order is prepared by a stenographer.
Source: Ralph M. Barnes, Motion and Time Study, 8th ed.
(New York: John Wiley & Sons, 1980), pp. 76–79.
Reprinted by permission of John Wiley & Sons, Inc.
Fundamentals of Operations Management 4e
Exhibit S10.2a
© The McGraw-Hill Companies, Inc., 2003
S10–5
Flow
Diagram
and
Process
Chart of
an Office
Procedure
—Present
Method*
*Requisition is written
by supervisor, typed
by secretary,
approved by
superintendent, and
approved by
purchasing agent;
then order is prepared
by a stenographer.
Source: Ralph M. Barnes,
Motion and Time Study, 8th
ed. (New York: John Wiley &
Sons, 1980), pp. 76–79.
Reprinted by permission of
John Wiley & Sons, Inc.
Exhibit S10.2b
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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Common Notation in Process Charting
Exhibit S10.3
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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Gilbreth’s Principles of Motion Economy
Source: Frank C. Barnes, “Principles of Motion Economy: Revisited, Reviewed, and Restored,” Proceedings
of the Southern Management Association Annual Meeting, Atlanta, GA, 1983, p. 298.
Fundamentals of Operations Management 4e
Exhibit S10.4a
© The McGraw-Hill Companies, Inc., 2003
S10–8
Gilbreth’s Principles of Motion Economy (cont’d)
Source: Frank C. Barnes, “Principles of Motion Economy: Revisited, Reviewed, and Restored,” Proceedings
of the Southern Management Association Annual Meeting, Atlanta, GA, 1983, p. 298.
Fundamentals of Operations Management 4e
Exhibit S10.4b
© The McGraw-Hill Companies, Inc., 2003
S10–9
WorkerMachine
Chart
for a
Gourmet
Coffee
House
Exhibit S10.5a
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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Worker-Machine Chart for a
Gourmet Coffee House (cont’d)
The customer, the clerk, and the coffee grinder (machine) are involved
in this operation. It required 1 minute and 10 seconds for the customer
to purchase a pound of coffee in this particular store.
During this time the customer spent 22 seconds, or 31% of the time
giving the clerk his order. He was idle during the remaining 69% of the
time. The clerk worked 49 seconds, or 30% of the time. The machine
was in operation 21 seconds, or 30% of the time.
Exhibit S10.5b
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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Activity Chart
of an
Emergency
Tracheotomy
Source: Data taken from
Harold E. Smalley and
John Freeman, Hospital
Industrial Engineering
(New York: Reinhold,
1966), p. 490.
Exhibit S10.6
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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Work Measurement
• Work Measurement
–The methodology used for establishing time
standards.
• Basic Industrial Engineering Methods
–Time study
–Elemental standard time data
–Predetermined motion-time data
–Work sampling
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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Types of Work Measurement Applied
to Different Tasks
Exhibit S10.7
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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Time Study
• Time Study
–The determination, with the use of a stopwatch,
of how long it takes to complete a task or set of
tasks.
–Normal time = Observed performance time per
unit x Performance rating
–Piece rate is the rate paid for work completed.
–Break down tasks by:
• Defining each work element.
• Separating human work from machine work.
• Defining operator and machine delays separately.
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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Elemental Standard-Time Data
• Time Standard
–The established time for completing a job, used
in determining labor costs associated with
making a product.
–Steps
• Breakdown the new job into its elements
• Match elements to the time for similar job-specific
elements in the elemental table.
• Adjust elements for special characteristics of the
new job.
• Add element times together and add delay and
fatigue allowances.
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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Predetermined Motion-Time Data
• Predetermined Motion-Time Tables
–Create a time standard for a job or task based
on standard times for basic motions (therbligs).
–Can be applied to a wide-variety of tasks.
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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Work Sampling
• Work Sampling
–A statistical technique for estimating how
workers allocate their time among various
activities throughout a workday.
–Issues involved:
• What level of statistical confidence is desired in
the results?
• How many observations are necessary?
• When should the observations be made?
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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Work Sampling (cont’d)
• Determining the Required Number of
Samples:
2
N
Z p(1  p)
E2
N = Number of observations to be made
Z = Number of standard deviations associated
with a given confidence level
p = Estimated proportion of time that the activity
being measured occurs
E = Absolute error that is desired
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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Work Sampling (cont’d)
• Steps in Conducting a Work Sampling Study:
–Identify the activities for study.
–Estimate the proportion of time of the activity of
interest to the total time.
–State the desired accuracy in the study results.
–Determine the specific time when each
observation is to be made.
–If using an estimated time, recompute the
required samples size at intervals during the
study and adjust the number of observations.
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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Assignment of Numbers to
Corresponding Minutes
Exhibit S10.8
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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Determination of Observation Times
Exhibit S10.9
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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Observation Schedule
Exhibit S10.10
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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Financial Incentive Plans
• Basic Compensation Systems
–Hourly pay
–Straight salary
–Piece rate
–Commissions
• Individual or Small-Group Plans
• Organizational Plans
–Profit sharing
–Gainsharing
Fundamentals of Operations Management 4e
© The McGraw-Hill Companies, Inc., 2003
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