6M Fishbone Diagram Template
The industry benchmark for Lean, Kaizen, and Six Sigma defect investigations. Systematically break down failures into Manpower, Machine, Material, Method, Measurement, and Milieu.
The Six M Categories Explained
Originally formalized by Dr. Kaoru Ishikawa, the 6Ms provide complete coverage of physical production systems.
1. Manpower (People)
Evaluates the human factors contributing to process defects or quality variance.
- Operator training, skill levels, and certification currency
- Fatigue, excessive overtime, or shift handoff communications
- Ergonomics, posture, and physical strain
- Compliance with documented standard operating procedures
"Torque wrench slipped due to operator unfamiliarity with new pneumatic model introduced on night shift."
2. Machine (Equipment & Tooling)
Examines hardware, automated systems, fixtures, and production tooling.
- Preventive maintenance status and bearing or gear wear
- Tooling wear, dull cutting blades, or degraded seals
- Sensor accuracy, PLC logic faults, and calibration drift
- Hydraulic pressure or electrical power stability
"Spindle bearing vibration exceeded 0.08mm after scheduled maintenance was deferred by 3 weeks."
3. Material (Raw Goods & Inputs)
Inspects raw stock, components, chemicals, and sub-assemblies entering the cell.
- Supplier lot-to-lot variance and out-of-spec incoming stock
- Chemical expiration, adhesive shelf life, or curing agents
- Contamination, oxidation, or packaging damage during transit
- Material handling and storage conditions
"Sheet metal alloy batch #408B exhibited 12% lower tensile strength than specified in purchase orders."
4. Method (Processes & Procedures)
Scrutinizes how operations are executed, sequenced, and monitored.
- Ambiguity in Work Instructions (WIs) or missing visual diagrams
- Line speed ramp-up during peak quotas violating cycle limits
- Inconsistent bolt-tightening sequences across workstations
- Inadequate changeover and setup verification checklists
"Visual SOP lacked tightening cross-pattern instructions for the 8-bolt cylinder head assembly."
5. Measurement (Inspection & Gauging)
Analyzes how data is collected, quantified, and verified on the line.
- Gauge Repeatability & Reproducibility (Gauge R&R) errors
- Zero-point drift on digital micrometers and calipers
- Sampling frequency too low to catch sporadic machine burrs
- Human inspector visual fatigue and inconsistent acceptance criteria
"Micrometer gauge had not been zero-calibrated against master block in 45 days, causing false passes."
6. Milieu / Mother Nature (Environment)
Considers environmental conditions surrounding the production process.
- Temperature swings causing thermal expansion of metal components
- Humidity variations disrupting adhesive curing and powder coats
- Airborne dust particulates contaminating cleanroom assembly
- Vibrations transmitted from neighboring heavy stamping presses
"HVAC failure raised bay humidity to 84%, preventing epoxy resin from curing properly before bake cycle."
Pairing 6M with the 5 Whys Technique
The 6M fishbone diagram groups your brainstormed factors into logical categories. To reach actionable root causes, drill down through sub-branches using iterative 5 Whys inquiry.
Example 5 Whys Chain on Machine (Equipment)
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Open the pre-configured 6M Ishikawa template directly on our interactive canvas. Auto-balances rib angles at 60° with instant vector SVG and PNG exports.