CQIA cheat sheet

Quality (ASQ): the totality of features and characteristics of a product or service that bear on its ability to satisfy stated or implied needs.

ISO 9000 defines quality as the degree to which a set of inherent characteristics fulfills requirements; grade is a category of requirements, not a measure of quality.

Cost of quality = prevention + appraisal + internal failure + external failure; prevention + appraisal is the cost of good quality, while internal + external failure is the cost of poor quality.

Cost of quality escalates downstream: roughly one dollar to prevent a defect, ten dollars to catch it at appraisal, one hundred dollars to fix it after the customer receives it.

Deming: 14 points, the PDCA/Shewhart cycle, abolish fear and numerical quotas; he asserted that management causes about 85% of quality problems.

Juran: the quality trilogy of planning, control, and improvement, plus the Pareto principle that a vital few causes produce most defects.

Crosby: quality is free, quality means conformance to requirements, the goal is zero defects, and the measure is the cost of nonconformance.

ISO 9001 rests on seven quality management principles: customer focus, leadership, engagement of people, process approach, improvement, evidence-based decision making, and relationship management.

Inspection detects defects after they occur, quality assurance prevents them through planned process controls, and a quality management system documents both.

Tuckman sequence: forming, then storming, then norming, then performing, then adjourning; a team can regress to an earlier stage when membership or goals change.

Effective team size is typically three to seven members; larger groups need structured facilitation and subdivided tasks.

Team charter elements: purpose, scope, customers, deliverables, authority, resources, milestones, roles, and ground rules.

Common team roles: sponsor or champion, leader or facilitator, recorder, timekeeper, and members; the recorder captures decisions and action items with owners and dates.

Brainstorming rules: no criticism during idea generation, freewheeling encouraged, quantity before quality, build on others' ideas, and evaluate only after generation stops.

Nominal group technique = silent idea writing, round-robin posting, clarification, then private ranking; it prevents one member from dominating the discussion.

Decision rules: unanimity requires everyone to agree, consensus requires everyone to support and commit, majority vote is fastest but can leave a losing minority uncommitted.

Thomas-Kilmann conflict modes are competing, collaborating, compromising, avoiding, and accommodating; collaborating fits situations where both the issue and the relationship matter.

A well-run meeting has an agenda issued in advance, agreed ground rules, minutes, and action items with named owners and due dates.

PDCA: Plan (define problem, target, and plan), Do (run the change on a small scale), Check (compare results with the target), Act (standardize or adjust); the cycle repeats rather than ending.

DMAIC = Define, Measure, Analyze, Improve, Control, for improving existing processes; DMADV = Define, Measure, Analyze, Design, Verify, for creating new designs.

Six Sigma target performance is 3.4 defects per million opportunities, roughly six sigma capability including the customary 1.5 sigma shift.

Takt time = available production time divided by customer demand over the same period; a cycle time greater than takt time means the process cannot meet demand.

5S order: sort (seiri), set in order (seiton), shine (seiso), standardize (seiketsu), sustain (shitsuke).

Eight lean wastes (TIMWOODS): transportation, inventory, motion, waiting, overproduction, overprocessing, defects, and unused skills.

Kaizen means small, continuous, low-cost improvement by the people doing the work; a kaizen event or blitz typically runs three to five days and ends with standardized changes.

A countermeasure is confirmed only when the same defect does not recur after the change; a fix that removes the symptom without the root cause will let the problem return.

Benchmarking types are internal, competitive, functional or process, and generic; benchmarking compares practices, not just metrics.

Seven basic quality tools: flowchart, check sheet, histogram, Pareto chart, cause-and-effect diagram, scatter diagram, and control chart.

Pareto principle: roughly 80% of effects come from 20% of causes; categories are plotted in descending order of frequency with a cumulative-percentage line.

Cause-and-effect diagram branches commonly use the 6M: manpower, machine, material, method, measurement, and Mother Nature (environment).

Control limits are not specification limits: control limits are calculated from process variation at center plus or minus three sigma, while specifications come from the customer.

Variable control charts (X-bar R, X-bar s, individuals) use measured data; attribute charts (p, np, c, u) use counted defectives or defects.

A histogram shows the distribution of one variable (shape, center, spread); a scatter diagram shows the relationship between two variables, and correlation does not prove causation.

FMEA risk priority number = severity times occurrence times detection, each scored 1 to 10; the highest RPN values are addressed first.

Flowchart symbols: oval = start or stop, rectangle = process step, diamond = decision, parallelogram = input or output, arrow = direction of flow.

Sampling choices: random gives every unit an equal chance, stratified samples within subgroups, systematic takes every kth unit, and sample size must be large enough to answer the question asked.