Six Sigma is a process-focused methodology designed to improve business performance through improving specific areas of a strategic business processes.
In this article we will discussed DMAIC six sigma overview model. DMAIC applies to an existing process that needs improvement.
It has described in five phases- Define, Measure, Analyze, Improve and Control.
Define phase- define the problem as a project. In this phase deliverables are six sigma alignments to business or customer needs, understanding the customer needs, prioritizing the customer needs, project selection and project scoping. Tools used in this phase are; QFD.CTQ drill down, voice of customer, kano analysis, brainstorming and multi-voting, SIPOC and scoping techniques.
Measure phase- validate the measurement system. Deliverables are process mapping at the micro level, sampling plan for the baseline and ensuring precision in measurement system. Tools for measurement phase are process mapping, sampling techniques and GRR study.
Analyze phase- establish process baseline, define performance goals, identify variation sources. In deliverables, calculate sigma multiple, form confidence intervals on sample data. This results in normal distribution, DPMO work sheets. Central limit theorem, sampling distributions, estimates/t-test, entitlement and benchmarking, ANOVA, Chi-square, F-test, poisson and binomial, brainstorming etc. tools are used in this phase.
Improve phase- quantify X's. it estimate the non causal X's, estimate prediction equation and best setting of X's, transfer Y flexibility to X's, screening design for experiments.
Control phase- control X's. Validate measurement system for X's and verify process improvement. In the last project sign off and GRR study done.