Quality Mgmt, Chapter 11

Six sigma represents a quality level of at most

3.4 defects per million opportunities or 3.4 dpmo

Six Sigma project might span an entire division or a narrow single production operation. factors that should be considered when selecting six sigma projects include

>financial return >impacts on customers and organizational effectiveness >probability of success >impact on employees >fit to strategy and competitive advantage

six sigma projects have three key characteristics

>problem to be solved >a process in which the problem exists >one or more measures that quantify the gap to be closed and can be used to monitor progress

lean production key tools include

The 5S's, visual control, efficient layout and standardized work, pull production, single minute exchange of dies (SMED), total productive maintenance, source inspection, continuous improvement

Applying six sigma to services requires examination of four key measures of the performance which are

accuracy, cycle time, costs, and customer satisfaction

cause-and-effect diagrams

analyze

pareto diagrams

analyze

scatter diagrams

analyze, improve

Quality problem-solving falls into one of five categories which are

conformance problems, efficiency problems, unstructured performance problems, product design problems, and process design problems

control charts

control

Flowcharts

define, control

5 S's

derived from Jap terms for sort, set in order, shine, standardize, and sustain.

The seven qc tools

flowcharts, check sheets, histograms, pareto diagrams, control charts

a six sigma quality level corresponds to a process variation equal to

half of the design tolerance while allowing the mean to shift as much as 1.5 standard deviation from the target.

six sigma project selection

is one of the most difficult challenges in six sigma. the problem is a deviation between what should be happening and what actually is happening

six sigma began as a

manufacturing focus to reduce defect levels to only a few parts per million

check sheets

measure, analyze

histograms

measure, analyze

process design problems involve designing

new processes or substantially revising existing processes. challenge is determining process requirements, generating new process alternatives, and linking these processes to customers needs.

product design problems involve designing

new products that better satisfy user needs

SMED

rapid changeover of tooling and fixtures in machine shops so that multiple products in smaller batches can be run on the same equipment. reducing setup time adds value to the operation and facilitates smoother production flow.

root causes

that condition having allowed or caused a defect to occur

one useful approach for identifying the root cause is

the 5 Why technique. this approached one to redefine a problem statement as a chain of causes and effects to identify the source of the symptoms by asking why, idealyy five times.

visual controls are indicator for

tools, parts, production activities that are placed in plain sight

unstructured performance problems result from

unsatisfactory performance by a poorly specific system. task is not standardized and not fully specified by procedures and requirements. require more creative approaches to solving.

conformance problems are defined by

unsatisfactory performance by a well-specified system. users are not happy with the system outputs such as quality or customer service levels.

efficiency problems problems are a result from

unsatisfactory performance from the standpoint of stakeholders other than customers. typical examples are cost and productivity issues. lean tool are often used for these problems.

pull production (also kanban or JIT)

upstream suppliers do not produce until the downstream customer signals a need for a part.