Process Analysis Terms



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.
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Process Flowcharting

Process flowcharting is the use of a diagram to
present the major elements of a process.
These basic elements can include:
 tasks or operations
 flows of materials or customers
 decision points
 storage areas or queues.

It is an ideal methodology by which to begin
analyzing a process.
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Flowchart Symbols
Tasks or
Operations
Decision
Points
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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.
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Flowchart Symbols
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(Cont.)
Storage areas
or queues
Examples: Sheds,
lines of people waiting
for a service, etc.
Flows of
materials or
customers
Examples: Customers
moving to their seat,
mechanic getting a
tool, etc.
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Example Flowchart:
Student Going to School
Go to
school
today?
Yes
Drive to
school
Walk to
class
No
Goof
off
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Process Flowchart - Improving the
Apartment Rent-Ready Process
1. Apartment
Unit Vacated
2. Trash Out
Unit
3. Assessment
to Turn
Unit/Make
Ready
4. Perform
Major
Repairs
5. Prepare for
Painting
6. Paint
7. Punch Out
8. Replace/
Repair Carpet
9. Clean Unit
10. Master Key
Unit
11. Arrange
Pest
Control
12. Inspect/
Light Clean
Daily Until
Rented
13. Apt Unit
Determined To
Be Ready
14. Application
Completed/
Approved
Apartment
Unit Rented
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Multistage Processes
Stage 1
Stage 2
Stage 3
Multistage Process with Buffer
Buffer
Stage 1
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Stage 2
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Multi-Stage Processes


Buffering
 Refers to a storage area between stages where the
output of a stage is placed prior to being used in a
downstream stage. Buffers allow stages to operate
independently. Work-in-process (WIP) inventory will
accumulate in the buffer.
No Buffering
 Blocking: Occurs when 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 Types of Processes

Make-to-order



Only activated in response to an actual order.
Both work-in-process and finished goods
inventory kept to a minimum.
Make-to-stock


Process activated to meet expected or
forecasted demand.
Customer orders are served from target stocking
level.
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Process Performance Metrics

Operation time = Setup time + Run time

Cycle time = Average time between

Throughput rate = 1/Cycle time

Throughput time = Average time for a unit to
completion of units
move through the system*
* Note: Little’s Law computes throughput time
while in (work-in-process) inventory only
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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?
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Bread-Making Operation
•
•
See pp. 113-114 (102-104 in old text). For
homework, construct a table, showing the amount
baked, amount packed, and WIP for each hour of
the day (3 eight hour shifts).
Calculate the Throughput Time in WIP Inventory
using Little’s Law; then calculate the Total
Throughput Time by adding the time in WIP
inventory to the baking and packing times.
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