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The Concept of Six Sigma begins with a process model and its implementation is called Business process Management (BPM) and the process of Six Sigma began at Motorola in the 1980’s. Six Sigma is the letter in the Greek alphabet used to denote Standard deviation, a statistical measurement of variation. Standard deviation can be thought of as a comparison between expected results or outcomes in a group of operations versus those that fail. With Six Sigma Standard deviation we arrive at 3.4 defects per million opportunities 0r 99.9997 percent this would mean that at six sigma, an airline would only loose three pieces of luggage for every one million that it handles. The Three primary elements of Six Sigma are Customers, Processes & Employees.
The objectives within the Define Phase which is first phase in DMAIC framework of Six Sigma are:-
Define the Project Charter
Assemble and train the team.
Project charters the charter documents the why, how, who and when of a project include the following elements
Work break down Structure
It is a process for defining the final and intermediate products of a project and their relationship. Defining Project task is typically complex and accomplished by a series of decomposition followed by a series of aggregations it is also called top down approach and can be used in the Define phase of Six Sigma framework.
The Second is Pareto Analysis which is a vertical bar graph showing problems in a prioritized order so it, so it can be determined which problems or opportunities should be tackled first. In the define phase the Pareto diagram is used in conjunction with the WBS to quantify the opportunities inherent in each of the tiny elements resulting from the WBS.
Deliverables: Six Sigma project focus on one or more of the following three deliverables: Cost, Quality and schedule. Factors Critical to Cost (CTC), include parameters that impact work in progress, finished goods inventory, overhead, delivery, material and labour, even when the costs can be passed on to the customer. Critical to Quality (CTQ) factors are perhaps most familiar to operational personnel since they directly impact the functional requirement specified by the internal and external customers. Critical to Schedule (CTS) factors impact the delivery time of the product or service.
Throughput Yield
For a process, throughput is a measure of the productivity of the process in producing error free product or service. For a product, throughput is a measure of the quality of the product of the entire product as a function of the quality of its various features.
The throughput yield is calculated based on the defects per unit (DPU) for each process step
DPU = #errors / # items
Y = 1- DPU
For example if there are 74 errors in products and 600 products DPU = 74/600 = 0.12 and Y = 1-0.12 = .88= 88%
Rolled Throughput Yield (RTY)
RTY summarises stepwise throughput yields for a multiple step process or multiple featured product. RTY is the measure of the overall quality level rolled throughput yield YRT for a N Step process is calculated using the formula YRT= Y1 * Y2* Y3 *… Y
In the Define Phase we also calculate the future value, present value and net present value of the project which the formulas are given in my earlier articles.
Process Maps
A process map is used in the define stage to document top level process activities and their stake holder.
Assembling the team
As soon as possible the project manager and project sponsor should arrange a short informal meeting with managers of all stakeholders groups to inform them that a project is proposed in their functional area with the permission and direction of the senior executives, this meeting represents an invitation for the middle managers to participate in the project by contributing a member of their team or to challenge the scope, objective or business needs addressed by the project proposal.
Further to conclude this forms the basic crux of the Define phase of Six Sigma in the DMAIC framework.
The Author Suresh V. Menon who has worked in various capacities as Project Manager, Principal Consultant (QA), Test Manager, and Implementation Manager & ERP Consultant can be contacted at test consultants@outlook.com for comments and queries.
