Six Sigma, JIT and Kanban

Six-Sigma

• Based on three concepts – Quality Control, TQM and Zero-defects

• Six Sigma or 6 σ is expected to have 99.99966% of products manufactured free from any defects or expected to have 3.4 problems-per-million products manufactured

• Two project Methodologies – DMAIC: Define, Measure, Analyse, Improve and Control – DMADV: Define Measure, Analyse, Design Verify

DMAICDMAIC DMADVDMADV

…used when product/process in a firm does not keep up to customers’ specification or not performing adequately

…used when product/process does not exist OR with or without DMAIC still does not meet customers’ requirements

• The first 3 measures are the same

• Data Intensive• Use of statistical tools• Implemented by Green

belts, Black Belts and Master Black Belts

SIMILARITIES

• DMAIC is about continuous improvement whereas DMADV is about Re-engineering

• DMAIC provides structure and rigor to problem solving while DMADV drives customer needs into product and service design

• DMAIC is correction while DMADV is prevention• DMAIC projects often take short durations to fix a problem while DMADV take

long durations as they are based on long-term business needs for new products/service

DIFFERENCESDIFFERENCES

Six-Sigma Criticisms• Offers nothing new• Overselling of Six-sigma through certifications that

claim expertise but having only basic knowledge• More of a corrective method than being proactive• Rigid because of its attention on variation• Limited success and no long-term improvements

proven• Processes cannot be normally distributed in the long-

run

Just-in-Time and Kanban

• Kanban means “signboard” or “billboard”• JIT can be achieved through Kanban• Kanban is signalling the scheduling system for

JIT production

A Switchgear Unit in Nashik

• Switchgears are electric power systems• One entire product was made from start to finish

by one cell combined with concept of kitting (providing enough material to reduce wastage)

• One shop had a board with different-colored bulbs that indicated the reasons for various bottlenecks. For instance, if there was no material or no order, a red bulb lit up; if the basket was full, a yellow bulb lit up, and so on.

Kanban, JIT in real-life?

To-do List In ProgressDone

Basic Principles•Visualize workflow•Limit work-in-progress•Pull work from column to column•Monitor, adapt, improve

Basic Principles•Visualize workflow•Limit work-in-progress•Pull work from column to column•Monitor, adapt, improve