Chapter 5 Process Analysis

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Chapter 5Process Analysis

• Process Analysis
• Process Flowcharting
• Categories of Processes
• Process Performance Metrics

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Process Analysis Terms

• Process Is any part of an organization that
  takes inputs and transforms them into outputs.
• Cycle Time Is the average 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.

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Other Process Terminology

• Blocking
• Occurs when the activities in a stage must stop
  because there is no place to deposit the item
  just completed
• Starving
• Occurs when the activities in a stage must stop
  because there is no work

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Other Process Terminology (Continued)

• Bottleneck
• Occurs when the limited capacity of a process
  causes work to pile up or become unevenly
  distributed in the flow of a process
• Pacing
• Refers to the fixed timing of the movement of
  items through the process

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Process FlowchartingDefined

• 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.

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Flowchart Symbols
Examples
Examples
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Flowchart Symbols (Continued)
Examples
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Example Flowchart of Student Going to School
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Multistage Process
Stage 1
Stage 2
Stage 3
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Multistage Process with Buffer
Buffer
Stage 1
Stage 2
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Categories of Processes

• Make-to-order
• Only activated in response to an actual order.
• Make-to-stock
• Process activated to meet expected or forecast
  demand.

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Types of Processes
Design
Source
Manufacture
Fabricate
Assemble
Distribute
Time
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Process Performance Metrics

• Throughput time
• Cycle time
• Throughput rate

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Process Performance Metrics (Continued)

• Velocity
• Operation time
• Efficiency

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Process Performance Metrics (Continued)

• Productivity
• Utilization

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Process Performance Metrics (Continued)

• Littles Law

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Cycle Time Example

• 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

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Example Continued

• What is the throughput rate?
• Answer
• If the actual output of units in 80 hours was
  550, what was the efficiency?
• Answer
• If the line was manned to run 80 hours over 2
  shifts, but was shut down for 8 hours, what is
  the utilization?
• Answer

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A machine produces box A at a rate of 30 per
minute. To switch the machine to A requires a
setup of 30 minutes. How long will it take to
make 10,000 As?

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If a refrigerator company has demand for 1000
refrigerators during a 7 hour shift, what is the
required cycle time of the line?

What is the throughput rate?

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You arrive at the customer service counter at
Wal-Mart to find 11 customers ahead of you. If
the counter can service 20 customers per hour,
what is your throughput time in minutes?
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Process Throughput Time Reduction

• Perform activities in parallel -
• Change the sequence of activities -
• Reduce interruptions -
• Reduce Distance -