Six Sigma
Chapter 1 – Overview of Six Sigma Management
Benefits of ‘Six Sigma’ Management
Improved Reduced
Process flows Total defects
Capacity and output Cycle times
Communication Work-in-progress
Customer and employee Inventory
satisfaction
Knowledge Unit costs
Productivity Time to market
Qulity and reliability
Delivery time
Benefits to stakeholders are a by-product of the organizational benefits.
The benefits to stakeholders include:
Stockholders more profit due to decreased costs and increased revenues
Customers delighted with products and services
Employees higher morale and more satisfaction in work
Suppliers a secure source of business
Process = A process is a collection of interacting components that transform inputs into
outputs toward a common aim, called a mission statement.
- It is the job of management to optimize the entire process toward its aim. This may
require the sub-optimization of selected components of the process
Voice of the process (VOP) = The distribution of
measurements of the outputs from a process over time.
The outputs from all processes and their component parts
may be measured; the measurements invariably vary over
time, and create a distribution of measurements. This is 6
sigma.
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,Variation in a process:
- Common cause variation = Consider a process such as
getting ready for work or class in the morning. Some days
you are busier than usual, while on other days you have less
to do than usual. Your process varies from day to day to
some degree.
- Special cause variation = However, if a construction project
begins on the highway you take to work or school, you might drastically alter your
morning routine. This would be special variation because it would have been caused
by a change external to your “driving to work or school” process.
Voice of the customer (VOC) = specification limits
- Quality is a concept whose definition has changed over
time. In the past, quality meant “conformance to valid
customer requirements.” That is, as long as an output fell
within acceptable limits, called specification limits, around
a desired value, called the nominal value (denoted by
“m”), or target value, it was deemed conforming, good, or
acceptable.
o USL = nominal + tolerance
o LSL = nominal – tolerance
- Taguchi loss function
Six sigma (non-technical)= management is the relentless and
rigorous pursuit of the reduction of variation in all critical processes
to achieve continuous and breakthrough improvements that impact
the bottom-line and/or top-line of the organization and increase
customer satisfaction.
Six sigma (technical) = The Normal Distribution. The term “Six Sigma” is derived from the
normal distribution used in statistics. Many observable phenomena can be graphically
represented as a bell-shaped curve or a normal distribution.
Feedback loop
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, Chapter 2 – Roles, Responsibilities and Terminology
Certification level:
1. Master Black Belt (MBB)
2. Black Belt (BB)
3. Green Belt (GB)
4. Yellow Belt (YB)
Senior executive = provides the impetus, direction and alignment necessary for Six Sigma’s
ultimate success
Executive committee member = the member are the top management of an organization
Champion = very active sponsorship and leadership role in conducting an implementing Six
Sigma projects.
Process owner = The manager of a process, has
responsibility for the process and has the authority to
change the process on his or her signature.
Responsibilities:
- Accountable for the monitoring, managing, and
output the process.
- Empower the employees who work in the process to
follow and improve the best practice method for the
process.
- Allocate the resources necessary for the project
(people, space, etc.).
- Accept, manage and sustain the improved process after completion of the Six Sigma
project.
- Ensure that process objectives and indicators are linked to the organization’s mission
through the dashboard (see Chapter 3).
- Understand how the process works, the capability of the process, and the
relationship of the process to other processes in the organization.
Critical-to-Quality (CTQ) = a measure of what is important to a customer
Unit = is the item to be studied with a Six Sigma project (e.g. product, component, service
(stap), or time period)
Defects & defectives:
- Defective = a non-conforming unit is a defective unit
- Defect = non-conformance on one of many possible, quality characteristics of a unit
that causes customer dissatisfaction
- Defect opportunity = each circumstance in which a CTQ can fail to be met. There
may be many opportunities for defects within a defined unit
o The number of defect opportunities generally is related to the complexity of
the unit under study. Complex units experience greater opportunities for
defects to occur than simple units
- Defect per Opportunity (DPO) = the number of defects divided by the number of
defect opportunities
- DPMO = equals DPO multiplied by one million
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