Process Analysis Terms

1
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.

2
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.

3
Flowchart Symbols
Examples Giving an admission ticket to a
customer, installing a engine in a car, etc.
Tasks or Operations
Examples How much change should be given to a
customer, which wrench should be used, etc.
Decision Points
4
Flowchart Symbols (Cont.)
Storage areas or queues
Examples Sheds, lines of people waiting for a
service, etc.
Examples Customers moving to their seat,
mechanic getting a tool, etc.
Flows of materials or customers
5
Example FlowchartStudent Going to School
Yes
Go to school today?
Drive to school
Walk to class
No
Goof off
6
Process Flowchart - Improving the Apartment
Rent-Ready Process
7
Multistage Processes
Multistage Process with Buffer
8
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.

9
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.

10
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 Littles Law computes throughput time
  while in (work-in-process) inventory only

11
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?

12
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 Littles Law then calculate the Total
  Throughput Time by adding the time in WIP
  inventory to the baking and packing times.