School of Engineering · Playlist

Lean Thinking and Improvement

Value and flow, the eight wastes, 5S, value stream mapping, and kaizen with standard work.

  1. Lean Value and Flow
  2. Eight Wastes: TIMWOODS
  3. 5S Workplace Organization
  4. Value Stream Mapping
  5. Kaizen and Standard Work
Lean and Quality/Continuous Improvement

Lean Value and Flow

Define customer value and improve the whole path from request to delivery.

Start with what the customer needs

Start with what the customer needs

Lean thinking improves how work creates value while reducing waste and respecting the people doing it. Value is judged from the customer's need: the right function and quality, in the needed quantity, at the needed time.

A busy machine is not proof of useful output. Making something early that nobody needs can increase storage and delay the work that is needed.

Separate value creation from necessary support and avoidable waste

Separate value creation from necessary support and avoidable waste

Value-added work changes the product or service toward the customer's requirement and is done correctly. Cutting a needed feature may add value; searching for a misplaced tool does not.

Some non-value-added work is currently necessary: required checks, safety measures and records protect customers and workers. Improve how that work is done; do not delete a safeguard because it does not physically change the product.

Supporting detail: Addendum 1 — Process time is not automatically value-added time.

Follow the work across handoffs

Follow the work across handoffs

Improving one station can build a queue at the next. Look at the whole path with Value Stream Mapping. Use Eight Wastes: TIMWOODS to describe problems and Kaizen and Standard Work to test improvements with the people doing the work.

5S Workplace Organization supports visible, repeatable work. It is one supporting method, not the whole of lean.

Lean and Quality/Continuous Improvement

Eight Wastes: TIMWOODS

Recognize eight patterns of wasted effort in manufacturing and daily life.

Use TIMWOODS to name what you observe

Use TIMWOODS to name what you observe

Transportation, Inventory, Motion, Waiting, Overproduction, Over-processing, Defects and Skills form TIMWOODS. Describe the observed problem before choosing a remedy.

Eight-cell TIMWOODS grid: Transportation, Inventory, Motion, Waiting, Overproduction, Over-processing, Defects and Skills.

Compare shop examples with everyday examples

Compare shop examples with everyday examples

These are illustrative examples, not descriptions of a particular shop.

Transportation: unnecessary material movement

Shop: A part travels to a distant holding area and back.
Daily life: Moving stored boxes between rooms without using them.

Inventory: excess material or work

Shop: Unneeded blanks fill a rack.
Daily life: Buying food that expires before use.

Motion: unnecessary movement by people

Shop: An operator searches several drawers for a tool.
Daily life: Searching for misplaced keys.

Waiting: idle time before work can proceed

Shop: A prepared job waits for missing information.
Daily life: A completed form sits awaiting approval.

Overproduction: too much or too early

Shop: Extra parts are made without demand.
Daily life: Printing copies nobody requested.

Over-processing: work beyond requirements

Shop: A hidden face receives an unnecessary cosmetic finish.
Daily life: Entering the same information into duplicate lists.

Defects: work that fails requirements

Shop: An incorrect hole pattern requires a replacement part.
Daily life: Retyping a form because of incorrect entries.

Skills: unused talent

Shop: An experienced operator's improvement idea is never considered.
Daily life: Ignoring a team member's relevant skill when dividing work.

Distinguish similar wastes before proposing a change; Practice

Distinguish similar wastes before proposing a change

Transportation follows material; motion follows people. Overproduction creates unwanted output; inventory is the resulting excess stock. Several wastes can occur together.

Inspection is not automatically a defect, and every machine cycle is not automatically wasted time. Check Lean Value and Flow. Buffers may be needed for supply variation; removing them without understanding demand and reliability can interrupt delivery.

Use 5S Workplace Organization to address searching and Kaizen and Standard Work to test a change. Improve the system rather than blaming the person caught in it.

Practice waste classification

Lean and Quality/Lean and Organization

5S Workplace Organization

The five-step workplace organization method. It is a lean manufacturing practice, and it is also why a tidy shop is a safer one.

Why 5S sits in a safety module

Why 5S sits in a safety module

5S is a lean manufacturing method for organizing a workplace. It earns its place here because most of what it asks for is also what keeps people from getting hurt.

A cluttered bench hides a hazard. An unlabeled container is an unknown chemical. A floor with chips on it is a slip. Every one of those is a 5S failure before it is an incident — which is why the shutdown steps in After operating any equipment are 5S in everything but name.

This page is the basics. 5S will get its own expanded treatment later.

Sort — Seiri

Sort — Seiri

  • Separate necessary items from unnecessary ones.
  • Remove or relocate items that do not belong in the work area.
  • Keep only what you need for the task in front of you.
Set in Order — Seiton

Set in Order — Seiton

  • Organize and label the remaining items clearly, for easy identification.
  • A place for everything, and everything in its place.
  • Create logical, efficient storage systems.
Shine — Seiso

Shine — Seiso

  • Clean work areas to maintain high hygiene standards.
  • Reduce accident risk through cleanliness and organization.
  • Inspect while cleaning — that is how problems get found early.

This is the step that overlaps most directly with safety — see the environment around the machine.

Standardize — Seiketsu

Standardize — Seiketsu

  • Establish consistent procedures for maintaining the first three S’s.
  • Create habits through regular practice and routine.
  • Ensure everyone follows the same organizational systems.
Sustain — Shitsuke

Sustain — Shitsuke

  • Continuously review and maintain all 5S practices.
  • Build the discipline to follow established procedures long-term.
  • Regular audits, and improvements to the system itself.
Lean and Quality/Continuous Improvement

Value Stream Mapping

Show material and information flow, then distinguish process time from elapsed lead time.

Map one product family from request to delivery

Map one product family from request to delivery

A value stream map (VSM) shows the steps and information that move a product or service toward the customer. Define the boundary and select work following a similar route. Walk the current process and record what happens, including queues and handoffs.

Show who requests work, how instructions reach production, where material moves and where it waits. An operations-only map misses the information controlling those operations.

Read process boxes, inventory triangles and flow arrows

Read process boxes, inventory triangles and flow arrows

Simplified map: customer order goes to planning, which instructs cutting. Material passes through cutting, inventory and assembly to the customer. Cutting takes 4 minutes, waiting 120 minutes and assembly 6 minutes.

This original sketch uses common conventions: a rectangle for a process, a triangle marked I for inventory, attached data boxes for measurements and arrows for flow. The legend distinguishes material movement from information. This is a teaching sketch, not a complete symbol standard.

Measure elapsed lead time separately from process time; Interactive; Practice

Measure elapsed lead time separately from process time

Lead time is elapsed time through the stated boundary, including waits. Process time is time actively spent doing the work within that boundary. Not all processing adds customer value.

Transfer size changes when jobs finish

10 jobs; A = 4 min/job, B = 6 min/job. Compare transfer-all with transfer-one.

Transfer all 10 jobs

First item 46 minFull order 100 minProcessing / job 10 min

AB0255075100Jobs 1–10 transfer at 40 minJob 1, station A: 0–4 min1Job 1, station B: 40–46 min1Job 2, station A: 4–8 min2Job 2, station B: 46–52 min2Job 3, station A: 8–12 min3Job 3, station B: 52–58 min3Job 4, station A: 12–16 min4Job 4, station B: 58–64 min4Job 5, station A: 16–20 min5Job 5, station B: 64–70 min5Job 6, station A: 20–24 min6Job 6, station B: 70–76 min6Job 7, station A: 24–28 min7Job 7, station B: 76–82 min7Job 8, station A: 28–32 min8Job 8, station B: 82–88 min8Job 9, station A: 32–36 min9Job 9, station B: 88–94 min9Job 10, station A: 36–40 min10Job 10, station B: 94–100 min10

Transfer 1 at a time

First item 10 minFull order 64 minProcessing / job 10 min

AB0255075100Jobs 1–1 transfer at 4 minJobs 2–2 transfer at 8 minJobs 3–3 transfer at 12 minJobs 4–4 transfer at 16 minJobs 5–5 transfer at 20 minJobs 6–6 transfer at 24 minJobs 7–7 transfer at 28 minJobs 8–8 transfer at 32 minJobs 9–9 transfer at 36 minJobs 10–10 transfer at 40 minJob 1, station A: 0–4 min1Job 1, station B: 4–10 min1Job 2, station A: 4–8 min2Job 2, station B: 10–16 min2Job 3, station A: 8–12 min3Job 3, station B: 16–22 min3Job 4, station A: 12–16 min4Job 4, station B: 22–28 min4Job 5, station A: 16–20 min5Job 5, station B: 28–34 min5Job 6, station A: 20–24 min6Job 6, station B: 34–40 min6Job 7, station A: 24–28 min7Job 7, station B: 40–46 min7Job 8, station A: 28–32 min8Job 8, station B: 46–52 min8Job 9, station A: 32–36 min9Job 9, station B: 52–58 min9Job 10, station A: 36–40 min10Job 10, station B: 58–64 min10

A is upper blue, B lower gold; bars are jobs, dashed lines completed-batch transfers. Minutes from order release 0; both plots share a scale.

Job 10 with transfer-one: 36 min waiting before A + 0 held for batch + 18 waiting at B = 54 min waiting. Add 10 min processing: 64 min elapsed from order release 0.

Ideal schedule: all equal jobs arrive at 0; serial single-job A then B, first come first served. A never blocks; waiting space is unlimited. Completed batches transfer immediately; the last may be smaller. Constant times; no setup, transport, failure, rework or variation. Finite-order illustration, not a factory forecast or a universal best batch.

Supporting detail: Addendum 2 — Default 10-job example: exact transfer-one schedule.

Supporting detail: Addendum 3 — Bounded model reference: scheduling equations and limits.

The transfer-batch experiment above schedules a whole order. The earlier map sketch uses a fixed queue for one item:

For one item in this simplified sequential example: cutting = 4 min, queue = 120 min, assembly = 6 min. Process time is 10 min; lead time is 130 min. No other delays or overlapping steps are included. Removing half the queue saves more elapsed time here than cutting one minute of processing.

Supporting detail: Addendum 4 — A queue suggests a question, not a proven cause.

Practice lead time

Practice transfer batches

Draw a future state and test a specific change

Draw a future state and test a specific change

A future-state map describes an improved flow to work toward. Choose a measurable change, assign responsibility and check the effect using Kaizen and Standard Work. Compare delivery, quality and workload across the whole stream.

Lean and Quality/Continuous Improvement

Kaizen and Standard Work

Use small measured experiments to improve work and preserve what the team learns.

Improve a specific problem with the people doing the work

Improve a specific problem with the people doing the work

Kaizen means continuous improvement. Start with an observed problem and a small change whose effect can be checked. Invite the people performing the task to explain what makes it difficult.

For example, repeated searching for a shared measuring tool may suggest a labeled location. Measure search time and check whether the location also works for the next user. This is an illustrative experiment, not a promised productivity gain.

Use Plan–Do–Check–Act to learn from a change

Use Plan–Do–Check–Act to learn from a change

  1. Plan: define the problem, measure the starting condition and predict the effect of a proposed change.
  2. Do: try an authorized change on a manageable scale and record what happens.
  3. Check: compare results with the prediction, including quality and unintended effects.
  4. Act: adopt and document an improvement, revise an uncertain idea or undo an unsuccessful change; begin the next cycle.

Plan leads to Do, then Check, then Act, with a return arrow to Plan for the next improvement cycle.

A useful result may be that the idea did not help. Keep that evidence rather than declaring success because something changed.

Use standard work as a baseline that can improve; Checklist

Use standard work as a baseline that can improve

Standard work records the current agreed method so people can repeat it and recognize departures. State the sequence, relevant timing, checks and materials needed. In repetitive production, standardized work also relates the sequence and required in-process stock to the pace of customer demand.

When an improvement is demonstrated, update the method and help everyone learn it. Do not bypass safety requirements or change controlled specifications as an informal experiment.

  • Record the problem and starting measure.
  • Describe one change and the expected result.
  • Test within applicable authorization and safety requirements.
  • Compare results and effects on other people or steps.
  • Update the agreed method if the evidence supports the change.

Use 5S Workplace Organization for workplace organization and Eight Wastes: TIMWOODS to name problems.

Supporting detail

Addendum

Additional evidence, standards context, and background referenced from the main text.

  1. Lean and Quality/Continuous Improvement/Lean Value and Flow

    Addendum 1. Process time is not automatically value-added time

    Rework takes processing time but corrects a failure. Inspection does not itself create the desired feature. A necessary machine cycle can transform the product even while the operator waits. Name whose time and which activity you are classifying.

    Back to reference 1

  2. Lean and Quality/Continuous Improvement/Value Stream Mapping

    Addendum 2. Default 10-job example: exact transfer-one schedule

    Fixed default example: 10 jobs; A = 4 min/job, B = 6 min/job; transfer one job at a time. This table does not update with live settings.

    Transfer 1 at a time · minutes from order release at 0
    JobA start–endTransferB start–endWait before AHeld for batchWait at BTotal wait
    10–444–100000
    24–8810–164026
    38–121216–2280412
    412–161622–28120618
    516–202028–34160824
    620–242434–402001030
    724–282840–462401236
    828–323246–522801442
    932–363652–583201648
    1036–404058–643601854

    Back to reference 2

  3. Lean and Quality/Continuous Improvement/Value Stream Mapping

    Addendum 3. Bounded model reference: scheduling equations and limits

    These equations describe the bounded ideal model; they do not report the current live settings.

    For job i: A start = (i − 1)tA; A end = i × tA; transfer = min(ceil(i / batch) × batch, N) × tA. B start is the later of transfer and previous B finish; B end = B start + tB. Waiting before A = A start; held for batch = transfer − A end; waiting at B = B start − transfer. The three waits plus tA + tB equal that job’s completion time from order release 0.

    Bounds: N 1–20 jobs, transfer 1–N, station times 1–20 whole min/job. This original scheduling example is separate from the map’s fixed 120-minute queue. It does not diagnose a factory or identify a universal optimal batch. Real setup, transport, limited space and variation can change the decision; no demand, quality or capacity forecast is made.

    Back to reference 3

  4. Lean and Quality/Continuous Improvement/Value Stream Mapping

    Addendum 4. A queue suggests a question, not a proven cause

    A queue may reflect a capacity constraint, batching, missing information or an unreliable next step. Observe demand, timing and variation before calling one operation the bottleneck. A working day and a calendar day are not interchangeable time units.

    Back to reference 4