Problem Solving
SMART, PDCA, Ishikawa, Pareto, RCA, 5 Whys, FMEA, DMAIC, 8D and the A3 report: the kit to diagnose and solve problems on the plant floor, for those just starting.
Real case
A hospital reduced patient falls in one unit by measuring with control charts and adding improvements one at a time. The average fell from 5.28 to 3.10 falls per week with the first two (a new reporting form and a multidisciplinary post-fall meeting) and ended at 1.94 with the full set: over 60% less.
Source: Health Quality Ontario case, cited in the MIT OpenCourseWare Six Sigma guide. See the article
10 articles
5 Whys: reaching the root cause by asking why, 5 times
Asking "why?" in a chain, five times, to stop attacking symptoms and reach the real root cause of a problem.
8D: the 8 disciplines for solving problems
8D is the 8-step method that Ford made the standard in the automotive industry: contain the damage right away, find the root cause afterward, and document that the problem will not come back.
A3 report: solving a problem on one sheet
The A3 is the one-page report Toyota uses to think through a problem from start to finish: background, current situation, goal, root cause, countermeasures, plan and follow-up. What matters is not the paper but the conversation between the person who writes it and the person who guides them.
DMAIC: the 5 phases of a Six Sigma project
DMAIC is the 5-phase structure (Define, Measure, Analyze, Improve, Control) that Six Sigma uses to organize a data-driven improvement project from start to finish.
FMEA: anticipating failures before they happen
FMEA (AMEF in Spanish) scores every possible failure mode from 1 to 10 on three axes — Severity, Occurrence and Detection — and multiplies them into a Risk Priority Number (RPN) to decide where to start acting, before the failure reaches the customer.
Ishikawa diagram (6M): how to find the root cause
The Ishikawa diagram sorts hypotheses about the cause of a problem into 6 categories (the 6Ms), so you do not settle for the first cause that "seems logical" before confirming it with data.
Pareto chart: prioritizing the 20% of causes that explain 80% of the problem
A Pareto chart ranks the causes of a problem from largest to smallest weight to show, with data, which handful of causes concentrates most of the impact — instead of spreading effort equally across all of them.
PDCA: the Plan-Do-Check-Act cycle
PDCA is the 4-step method for testing an improvement in a short, controlled cycle, using data, instead of rolling out a big change and hoping it works.
Root Cause Analysis (RCA): the umbrella over 5 Whys, Ishikawa and Pareto
RCA is not just another technique: it is the multi-step process within which 5 Whys, Ishikawa and Pareto are used to reach the real cause of a problem, instead of just covering up the symptom.
SMART objectives: how to write one that works
SMART turns a vague intention into an objective with a number, an owner and a date — the difference between a good resolution and a commitment that can be tracked and closed.