Lean playbook for industrial and HVAC equipment makers

1. 1

   Long lead times in high-mix production

   Many models and options in small batches mean units wait between operations far longer than they are worked on. Work in progress fills the floor and due dates are met by expediting.

   Lean methods

   • Value stream mapping (VSM)
   • Lead time
   • Heijunka
   • Pull system

   First moves

   1. Map the value stream for one product family, from order to shipping, with the waiting time at each step.
   2. Set a limit on work in progress between the main operations and release work to the floor only when there is room.
   3. Level the mix of models released each day instead of building in large runs of one model.

   Number to watch: Lead time from order release to shipping, and work in progress.

   Future state value stream map worksheetLead time worksheetHeijunka box planner (production leveling)Lead time calculatorThroughput time calculator
2. 2

   Complex assembly that lives in a few heads

   A unit can take hundreds of steps, torque values and wiring checks. The real method lives with a few experienced assemblers, and instructions, if they exist, lag behind engineering changes.

   Lean methods

   • TWI Job Instruction
   • Standard work
   • Digital work instructions
   • One-point lesson (OPL)

   First moves

   1. Write job breakdown sheets for the builds with the most errors, with key points and the reasons for them.
   2. Add photos, torque values and test limits to each instruction and update it with every engineering change.
   3. Capture expert tips as one-point lessons and review them at shift start.

   Number to watch: Build errors found at test, by station.

   TWI job breakdown sheetManufacturing process instruction (MPI) templateOne point lesson (OPL) template
3. 3

   Stations only one person can run

   Skilled assemblers, welders and test technicians take years to develop. When one is off or retires, a station stands idle or work goes to someone who has never done it.

   Lean methods

   • Skills matrix
   • Cross-training
   • Job cover matrix

   First moves

   1. Build a skills matrix by station and mark every job fewer than three people can do.
   2. Plan cross-training for those jobs first, with sign-off by the expert.
   3. Review the matrix monthly and before planned absences and retirements.

   Number to watch: Jobs with fewer than three trained people.

   Skills matrix templateCross-training plan templateCompetency assessment form
4. 4

   Rework after final test

   Leaks, wiring faults and failed run tests at the end of the line send units back for rework, after panels are closed and more work has been added. The same failures repeat because the cause is not traced back to the station.

   Lean methods

   • Quality at the source
   • Pareto analysis
   • Poka-yoke
   • Root cause analysis (RCA)

   First moves

   1. Pareto test failures by cause and by the station where the fault was made.
   2. Test sub-assemblies, such as refrigerant circuits or wiring harnesses, before they are closed in.
   3. Error-proof the top causes, for example connectors that only fit one way, and run root-cause analysis on the rest.

   Number to watch: First pass yield at final test, and rework hours.

   Pareto chart templateDefect check sheetPoka-yoke worksheetRoot cause analysis templateFirst pass yield (FPY) calculatorCost of poor quality (COPQ) calculator
5. 5

   Quality of bought-in parts

   Castings, motors, compressors, controls and sheet metal come from many suppliers. A bad lot found at final test costs far more than one caught at receiving.

   Lean methods

   • Incoming inspection
   • Supplier scorecard
   • Supplier corrective action request (SCAR)
   • Acceptance quality limit (AQL)

   First moves

   1. Inspect the parts with the worst history at receiving, with a sampling plan.
   2. Send each key supplier a monthly scorecard on quality, delivery and response time.
   3. Raise a SCAR for repeat problems and track the supplier's response.

   Number to watch: Supplier defects per million, and defects found at receiving against defects found later.

   Incoming inspection checklistSupplier scorecardSupplier corrective action request (SCAR) form
6. 6

   Assembly waiting for parts

   A unit is started, then parked because one part is missing. Assemblers search the stores, and half-built units take up floor space.

   Lean methods

   • Kanban
   • Mizusumashi (water spider)
   • Milk run

   First moves

   1. Log every shortage with the part, the unit affected and the cause, and review it weekly with planning and purchasing.
   2. Kit the parts for each unit before it is released, so a shortage shows before work starts.
   3. Use two-bin kanban for hardware and consumables at the stations.

   Number to watch: Line stops and parked units caused by missing parts.

   Material shortage logWater spider route plan (mizusumashi)Kanban card template
7. 7

   Heavy lifts, welding and pressure testing

   Heavy lifts, welding, brazing, pressure testing and machine servicing all carry serious risk. Near misses go unreported when reporting is a hassle, and lockout procedures go out of date.

   Lean methods

   • Near miss
   • Lockout/tagout (LOTO)
   • Behavior-based safety (BBS)

   First moves

   1. Write a job safety analysis for lifting, pressure testing and other high-risk tasks, with the crew.
   2. Write machine-specific lockout procedures with a photo of every isolation point.
   3. Make near-miss reporting quick, and tell people what changed after each report.

   Number to watch: Near misses reported and closed, and the recordable injury rate.

   Job safety analysis (JSA) templateLockout/tagout (LOTO) procedure templateNear miss report form

More small fixes in the production, quality and warehouse and logistics sections of the kaizen idea bank.

Free templates, calculators and buyer's guides

• Future state value stream map worksheetThe eight future-state questions worked through in order: takt, pitch, flow, supermarkets, the pacemaker and the mix, with an EPEI check and current against future lead time.
• Lead time worksheetProduction lead time from the inventory waiting at each step, value-added time and process cycle efficiency, plus an order traced from order to delivery.
• Heijunka box planner (production leveling)Weekly demand turned into containers a day, takt, pitch and slots, a leveled sequence of products and the heijunka box, with a check that the changeovers fit.
• TWI job breakdown sheetThe TWI Job Instruction breakdown of a job into important steps, key points and reasons, with a worked example and the four steps.
• Manufacturing process instruction (MPI) templateOperation steps with parameters, tools, quality checks, safety and a photo each, plus revision history and approval.
• One point lesson (OPL) templateOne topic on one page: wrong way and right way pictures, key points, why it matters and a sign-off record.
• Skills matrix templatePeople by skills, a 0 to 4 scale, a training column and a coverage row that shows the gaps.
• Cross-training plan templateWho is learning which task, from and to which level, by when, and how many are qualified on each task.
• Competency assessment formEach task rated 0 to 4 on the skills matrix scale with the evidence seen, then the gaps and a training plan.
• Pareto chart templateA tally sheet, the categories sorted largest first with cumulative %, and the chart. Excel does the sorting and drawing.
• Defect check sheetTally defects by type and day, with units inspected, defect rates, a location sheet and the week's Pareto.
• Poka-yoke worksheetEach step's possible errors, prevention or detection, the method, a device idea and a verified box.
• Root cause analysis templateOne report from problem statement to proof: containment, evidence, analysis, verified causes, actions and the effectiveness check.
• Incoming inspection checklistReceiving inspection checks from paperwork to sample, the sampling plan, the decision, and an Excel log by supplier.
• Supplier scorecardMonthly PPM, on-time delivery and SCAR measures turned into points, a weighted score and a rating per supplier.
• Supplier corrective action request (SCAR) formA SCAR from the problem and containment asked for to the supplier's 8D-style response, verification and closure.
• Material shortage logEvery part short with its need date, line impact, ETA and escalation, and counts by reason and supplier.
• Water spider route plan (mizusumashi)A water spider's fixed route: stops with arrival times, what is delivered and collected, route time against the cycle, cart load and a trip log.
• Kanban card templateSix production and six withdrawal kanban cards to print and cut out, with loop sizing and a card register.
• Job safety analysis (JSA) templateJob steps, hazards, risk scored before and after the controls, the hierarchy of controls, PPE and sign-off.
• Lockout/tagout (LOTO) procedure templateA machine-specific LOTO procedure: energy sources and isolation points, the steps from shutdown to restart, and the annual review.
• Near miss report formA two-page near miss report from the first report to closure, and an Excel log with status and days open.
• 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.
• 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.