Problem Solving

5 Whys Sakichi Toyoda / Toyota Production System, early 20th century Ask "why?" five times in succession to drill past surface symptoms into the true, fixable root cause of any problem. Fishbone Diagram (Ishikawa Diagram) Kaoru Ishikawa, 1960s Map multiple contributing causes across categories — essential for the messy, multi-cause problems where blaming one thing always misses the point. PDCA Cycle (Plan–Do–Check–Act) Walter Shewhart / W. Edwards Deming, 1930s–1950s The iterative improvement loop that separates creators who actually get better from those who just keep staying busy. Theory of Constraints Eliyahu Goldratt, 1984 Every system has one primary bottleneck limiting all throughput — find it, exploit it, elevate it, then find the next one. Systems Thinking Jay Forrester / Peter Senge, 1950s–1990s View problems as part of interconnected feedback loops — the lens that reveals why your quick fix made things worse and how to intervene without creating downstream problems. A3 Problem Solving Toyota Production System, formalised 1960s–80s Fit everything that matters about a problem on one sheet of paper — if it doesn't fit, you don't understand it well enough yet. Appreciative Inquiry David Cooperrider & Suresh Srivastva, 1987 Instead of analysing what's broken, study what's working brilliantly and build more of it — a strengths-based approach that often produces faster results than deficit analysis.