Free tool
Fishbone diagram maker
A fishbone diagram, also called an Ishikawa or cause-and-effect diagram, sorts the possible causes of one problem under categories such as the 6Ms. Type the problem and the causes below, and the tool draws the diagram for you to download.
Headequalsthe one problem, stated as a fact
BonesequalsManpower, Machine, Method, Material, Measurement, Mother nature
Causesequalspossible reasons under each bone, one per line, tested afterwards
One specific problem, with where and how often if you know
Pre-filled with the worked example. The six bones start as the 6M categories; rename them to fit your problem. Your text stays in your browser.
Causes on the diagram
8
Each one is a possibility to test, not yet a finding.
Manpower
2
Machine
2
Method
1
Material
1
Measurement
1
Mother nature
1
Next step
Want to keep problem solving in one place?
Bring this result to a 45-minute demo and we will show where it fits in LeanSuite's AI Root Cause Analysis.
How to use it
Brainstorm wide, then test
State the problem as a fact. “Labels applied crooked on Line 2” works; “poor quality” does not. Where and how often helps.
Fill one bone at a time. Ask what under that heading could produce the problem, and give each answer its own line. The bones start as the 6Ms; rename them if your process needs other headings.
Mark the likely causes and go and check them. The diagram is a list of possibilities. Take the few that fit the facts to the work area, then use the 5 Whys canvas on the ones you confirm. Our fishbone examples show five worked manufacturing problems.
Worked example
Illustrative numbers, not a benchmarkA packing line applies labels crooked on Line 2. The team fills the six bones.
- 1Head: “Labels applied crooked on Line 2”.
- 2Manpower: new operators not trained on the applicator; shift handover skips the label check.
- 3Machine: applicator guide is worn; conveyor speed drifts during the shift.
- 4Method: no setup check for label position. Material: label roll tension varies between supplier lots.
- 5Measurement: position is judged by eye, no gauge. Mother nature: humidity on the packing floor weakens the adhesive.
Embed this tool
Teaching this, or writing about it? Paste this code into your site, course page or intranet and the tool works right there. It is free, with no sign-up.
<iframe src="https://www.theleansuite.com/tools/fishbone-diagram-maker/embed" title="Fishbone diagram maker by LeanSuite" width="100%" height="3300" style="border:0;max-width:1000px" loading="lazy" allow="clipboard-write"></iframe>
<p style="font:13px/1.4 sans-serif"><a href="https://www.theleansuite.com/tools/fishbone-diagram-maker">Fishbone diagram maker</a> by LeanSuite</p>How LeanSuite helps
LeanSuite's AI Root Cause Analysis helps teams work through the causes of a problem and keep the analysis with the corrective action that follows.
See AI Root Cause AnalysisRead more
- Free template: Root cause analysis template
- Fishbone diagram in the lean glossary
- Fishbone Diagram: A Root Cause Analysis Visual Tool
- Free template: Fishbone diagram template (6M), printable with an Excel cause list
- Fishbone diagram examples: five worked manufacturing problems
- Fishbone Diagram: A Root Cause Analysis Visual Tool
- Root cause analysis: the method guide
- The 6Ms in the lean glossary
- Fishbone diagram guide: draw one, read it and turn it into checks
- The 6 Ms of production: what each bone covers
- Problem solving methods compared
- 5 Whys canvas: take a confirmed cause to its root
- Pareto chart maker: choose which problem to analyse
FAQ
Fishbone diagram maker: common questions
A fishbone diagram, also called an Ishikawa or cause-and-effect diagram, is a picture of the possible causes of one problem. The problem is the head of the fish, and the causes hang off the bones, grouped by category. It helps a team brainstorm widely and not stop at the first idea. The causes it lists still have to be tested with facts.
Manpower (people), Machine, Method, Material, Measurement and Mother nature (the environment). They are a checklist of places to look in a manufacturing process, so that the team does not only think about the machine. You can rename or replace them: service and office processes often use categories such as policies, procedures, people and systems.
Write one specific problem in the head. Pick the categories for the bones. Ask the team what could cause the problem under each category and write one cause per line, adding the reasons behind a cause as separate lines. Then choose the few most likely causes and test them with data or a check at the work area. This tool draws the diagram as you type.
No. It is one tool inside a root cause analysis. A fishbone organises the possible causes. It does not prove which one is real. After the brainstorm, verify the likely causes with evidence, and use a method such as the 5 Whys on the confirmed ones to get to a cause you can fix.
Yes. Download PNG gives an image for a slide or a report, and Download SVG gives an editable vector file for a design tool or print. The diagram is drawn in your browser from what you type, and nothing you enter is sent to or stored on our servers.
More free lean tools
All tools- OEE calculatorOverall equipment effectiveness from shift time, downtime, ideal cycle time and part counts.
- Downtime cost calculatorWhat an hour, an event and a year of unplanned downtime cost, from lost output, idle labour, scrap and overtime.
- SMED changeover calculatorTime saved by moving changeover steps from internal to external, capacity freed per week and the smaller batch it allows.
- Takt time calculatorThe pace a line must hit to meet customer demand, from shift time, breaks and daily demand.
- Cycle time calculatorCycle time against takt, units per hour, capacity per shift and the gap to daily demand.
- Line balancing calculatorLine efficiency, balance delay and the minimum number of stations from station times and takt.
- Bottleneck calculatorThe step that limits your line, from each step's cycle time, machines and uptime, with daily capacity and the gap to demand.
- First pass yield (FPY) calculatorFirst pass yield at each step and rolled throughput yield (RTY) across the whole process.
- Cost of poor quality (COPQ) calculatorTotal COPQ and cost of quality, and each as a share of revenue, from the four quality cost categories.
- Process capability (Cp, Cpk) calculatorCp and Cpk against your specification limits, plus Pp and Ppk from pasted measurements, with a distribution chart.
- DPMO and sigma level calculatorDPMO, defects per unit, yield and sigma level from the defects found, units checked and opportunities per unit.
- MTBF and MTTR calculatorMean time between failures, mean time to repair and availability from operating time, failures and repair time.
- Lead time calculatorManufacturing lead time from WIP and throughput (Little's Law), and the share of it that adds value.
- Throughput time calculatorThroughput time from process, inspection, move and wait time, the share of it that adds value, and units per hour.
- Kaizen savings calculatorYearly savings, payback in months and first-year ROI of an improvement, from time saved, scrap avoided and its costs.
- TEEP calculatorTotal effective equipment performance: OEE multiplied by how much of all calendar time you plan to run.
- Overall labor effectiveness (OLE) calculatorHow well paid labor hours turn into good output: availability, performance and quality of the crew.
- Inventory turnover and days on hand calculatorHow many times stock turns over in a period and how many days of it you hold, from COGS and average inventory.
- Safety stock calculatorSafety stock and reorder point from the service level you want, average demand and lead time, and how much each varies.
- Scrap rate calculatorScrap rate, the cost of scrap per period and per year, and what reaching a target rate would save.
- TRIR and DART rate calculatorOSHA recordable and DART incident rates from your 300A case counts and hours, and what one more case does to them.
- NIOSH lifting equation calculatorRecommended weight limit and lifting index for a two-handed lift, with every multiplier shown so you can see what to redesign.
- Time study sample size calculatorHow many cycles of an element to time, from your first readings, with the t formula, the ILO formula and the range method.
- Maintenance strategy selectorAnswer the RCM questions for one failure mode and get the maintenance strategy, the reasoning and the check or test interval.
- Noise dose and TWA calculatorDose and 8-hour TWA for a shift of noise levels under OSHA and NIOSH, which limits are reached and how much loud time to cut.
- Repair or replace calculatorEquivalent annual cost of keeping and repairing an old machine against buying a new one, with each one's economic life and the break-even figures.
- Compressed air leak cost calculatorAir lost, kW and cost a year for each tagged leak from its size and the pressure, ranked so the biggest gets fixed first.
- Machine hour rate calculatorWhat one productive hour of a machine costs, with and without the operator, the cost per part and how utilisation moves the rate.
- Acceptance sampling calculatorRead the OC curve and the real risks of a sampling plan, find the plan for your AQL and LTPD, or size a zero-defect test.
- Shift schedule plannerTen shift patterns on real dates: calendar for each crew, hours a week, weekends off, coverage and the weeks over 40 hours.
- Pareto chart makerPaste categories and counts: sorted bars, cumulative percentage line and the vital few at the 80% line, as a PNG or SVG.
- Histogram makerPaste measurements: the histogram with automatic or chosen bins, plus mean, median and standard deviation, as a PNG or SVG.
- Box plot makerPaste one or more groups of numbers: box plots with quartiles, IQR, whiskers and outliers by the 1.5 IQR rule, as a PNG or SVG.
- 5 Whys canvasWrite the problem, answer up to five whys, state the root cause and countermeasure, then print the one-page canvas.
- Lean maturity self-assessmentScore 24 statements across eight dimensions and get a result band for each, an overall band and where to start.
- Lean method navigatorSix questions about one problem, then the lean method to start with, the two that follow, why each fits, five steps for Monday and what it will not solve.
- Manufacturing ROI calculatorAnswer a few questions about your shop floor, shifts and downtime to estimate your potential ROI with LeanSuite.