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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 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

Examples: Giving an admission ticket to a customer, installing a engine in a car, etc.

Decision Points

Examples: How much change should be given to a customer, which wrench should be used, etc.

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Flowchart Symbols (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

Yes

No

Goof off

Go to school today?

Walk to class

Drive to school

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1. ApartmentUnit Vacated

2. Trash OutUnit

3. Assessmentto Turn

Unit/MakeReady

4. PerformMajor

Repairs

5. Prepare for Painting

6. Paint 7. Punch Out8. Replace/

Repair Carpet9. Clean Unit

10. Master KeyUnit

11. ArrangePest

Control

12. Inspect/Light CleanDaily Until

Rented

13. Apt UnitDetermined To

Be Ready

14. ApplicationCompleted/Approved

ApartmentUnit Rented

Process Flowchart - Improving the Apartment Rent-Ready Process

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Multistage Processes

Stage 1 Stage 2 Stage 3

Multistage Process with Buffer

Stage 1 Stage 2

Buffer

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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 completion of units

Throughput rate = 1/Cycle time

Throughput time = Average time for a unit to 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.