1. IENG 451 - Lecture 05 Process Tools:
Process Capability; SIPOC and Swim Lane Diagrams
5/10/2018
IENG 451 Operational Strategies
(c) D.H. Jensen

2. IENG 451 Operational Strategies
Six Sigma - Motorola
Six Sigma* = 3.4 defects per million opportunities!
± 6 standard deviations – after a 1.5 sigma shift!
Every Motorola employee must show bottom line results of quality project – finance, mail room, manufacturing, etc.
identify problem;
develop measurement;
set goal;
close gap
Long term process – 5 years to fully implement
5/10/2018
IENG 451 Operational Strategies
(c) D.H. Jensen

3. Two Process Capability Indices
Cp:
Measures the potential capability of the current process - if the process were centered within the product specifications
Two-sided Limits:
One-sided Limit:
5/10/2018
IENG 451 Operational Strategies

4. Cp Relation to Process Fallout
Recommended Minimum Cp Ratios: (D. C. Montgomery, 2001)
Existing Process (1-sided) 1.33 (2-sided)
Existing, Safety / Critical Parameter
New Process
New, Safety / Critical Parameter
5/10/2018
IENG 451 Operational Strategies

5. Process Capability Indices
Cpk:
Measures actual capability of current process - at its’ current location with respect to product specifications
Formula:
Where:
5/10/2018
IENG 451 Operational Strategies

6. Process Capability Indices
Regarding Cp and Cpk:
Both assume that the process is Normally distributed
Both assume that the process is in Statistical Control
When they are equal to each other, the process is perfectly centered
Both are pretty common reporting ratios among vendors and purchasers
5/10/2018
IENG 451 Operational Strategies

7. Process Capability Indices
Two very different processes can have identical Cpk values, though:
because spread and location interact in Cpk!
USL
LSL
5/10/2018
ENGM 720: Statistical Process Control

8. Process Capability Indices
Cpm:
Measures the current capability of the process - using the process target center point within the product specifications in the calculation
Formula:
Where target T is:
5/10/2018
ENGM 720: Statistical Process Control

9. IENG 451 Operational Strategies
SIPOC
Is an acronym for a diagram covering flow:
Suppliers
The external / internal entities providing the
Inputs
The items that flow into the scope of your
Process
The steps (actions) within your scope to produce
Outputs
The items that flow from your process scope to the
Customers
The external / internal entities using your outputs
5/10/2018
IENG 451 Operational Strategies
(c) D.H. Jensen

10. IENG 451 Operational Strategies
SIPOC
Keys for a SIPOC diagram:
Identify the scope
These are the process boundaries and activities
Model at a high level now, lower model level with VSM
Identify the KPOVs and customers
Brainstorm these items
If there are too many, focus on the critical few or go to a higher level
Identify the KPIVs and suppliers
5/10/2018
IENG 451 Operational Strategies
(c) D.H. Jensen

11. IENG 451 Operational Strategies
SIPOC
Keys for a SIPOC diagram:
Identify the Process Steps and CTQs
These are the internal activities within the process boundaries
Critical To Quality requirements must be met by the process
Order of keys does not matter for a SIPOC diagram:
Definitions (being specific) does matter
Timing information is important (constraints)
All members must understand the diagram
Check definitions and scope alignment at the end
5/10/2018
IENG 451 Operational Strategies
(c) D.H. Jensen

12. IENG 451 Operational Strategies
Swim Lane Charts
These diagrams highlight WHO handles the flow:
Identify the different people / functions that are involved in the process
These are listed on the left side (vertical access)
Timing is shown on horizontal access
These become the swim lanes
Brainstorm the steps in the Process (SIPOC):
Identify them on notes / cards for As-Is, re-use for To-Be
Place them in the proper swim lane, in order, connect flows
Connect the notes / cards with arrows showing flow direction
Communications are noted with thin lines, show informal communications with dashed, thin lines
5/10/2018
IENG 451 Operational Strategies
(c) D.H. Jensen

13. IENG 451 Operational Strategies
Questions & Issues
5/10/2018
IENG 451 Operational Strategies
(c) D.H. Jensen