Standard Work

← All maturity guides

SEF Reference Guide G06  |  Manufacturing OpEx Maturity Assessment

What it is

Standard work is the current best known way to do a job, written down, trained, and followed, so the result is the same no matter who is on shift. It is not a rulebook handed down from engineering. It is the agreed method the team uses today, and the starting point for the next improvement.

Three layers work together. The SOP says what the process must do and to what requirements. The job instruction shows the operator how to do each step, including the key points that make or break quality and safety. Boundary samples show, with real parts, where good ends and bad begins. When all three exist and people are trained and certified against them, quality stops depending on who happens to be working.

The idea has two main roots. The US Training Within Industry (TWI) program of World War II taught supervisors to break jobs into important steps, key points, and reasons, and to instruct people in a set sequence. Toyota later built that into standardized work, defined by three elements: takt time, the work sequence, and the standard in-process stock needed to run smoothly.

Why it matters

• Quality: Most variation between shifts comes from people doing the same job different ways. One method means one result.
• Cost: Less scrap and rework, and faster training. New people reach full speed sooner when the method is written and taught the same way every time.
• Delivery: A standard cycle makes output predictable, so planners can trust the capacity numbers.
• Safety: Key points capture the hazards and the safe way to handle them. People stop learning safety by getting hurt.
• Improvement: Without a standard you cannot tell whether a change made things better. The standard is the baseline every improvement is measured against.

Key terms

Term	Meaning
Standard Work	The current best method for a job, defined by takt time, work sequence, and standard in-process stock, documented, trained, and followed, and the baseline for the next improvement.
SOP	Standard Operating Procedure. The written, approved method for performing a process: purpose, scope, requirements, steps, and responsibilities.
Boundary samples	Physical examples of acceptable and unacceptable product kept at the point of inspection so everyone judges quality the same way. Also called limit samples.
Job instruction	A one-page, operator-level breakdown of a job into important steps, key points, and reasons. Visual, usually with photos.
Key point	Anything in a step that makes or breaks the job: quality, safety, or a knack that makes it easier.
Takt time	Available working time divided by customer demand. The pace the job must meet.
Work sequence	The exact order in which the operator performs the work elements within takt.
Standard in-process stock	The minimum parts in the station or machines needed to keep the sequence running without waiting.
Certified training	Training that ends with a documented sign-off by a qualified trainer that the person can do the job to standard, unassisted.
Re-standardize	Updating the SOP, job instruction, and training after an improvement so the new method becomes the only method.

How to do it

1. Pick a pilot job. Choose one with visible variation between people or shifts, or a recent quality escape. Short cycle jobs are easiest to start with.
2. Observe the best operator. Watch the job at the workplace several times. Time each work element. Note where people differ and which way gives the best result.
3. Agree the method. Bring the operators, the team leader, and a quality or process engineer together. Settle on one sequence. Where there is disagreement, try both and measure.
4. Write the SOP. One per process. State purpose, scope, inputs, requirements, steps, and owner. Keep it short and put it under document control.
5. Write the job instruction. One per job. List the important steps (what), key points (how), and reasons (why). Use photos. Put it at the workstation, not in a binder in the office.
6. Make boundary samples. For every visual or attribute check, collect real good, marginal, and bad parts. Label them, get quality sign-off, and store them at the inspection point. Replace them on a set schedule because samples wear and fade.
7. Move checks into the line. Add quality checks at the key points where defects are created, not only at final test. Each check references its boundary sample.
8. Train and certify. Use the four TWI steps: prepare the learner, present the job, have them try it, and follow up. Sign off only when the person can do it unassisted to standard. Record it in the skills matrix (see G16).
9. Audit adherence. Team leaders check one job per shift against the instruction. Differences are either retraining needs or signs the standard is wrong.
10. Re-standardize after every improvement. Build a rule into your improvement process: no project closes until the documents and training are updated.

What each maturity level looks like

QS-1 Standard Work

Level	Assessment wording	What it looks like on the floor	How to move up
1	Quality is only checked at the end of the line.	Final inspection catches defects hours or days after they were made. Each operator does the job their own way.	Identify the three points where most defects are created and add checks there.
2	Good and bad examples (boundary samples) are used for quality checks at key points along the line.	Labeled good and bad parts sit at in-line check stations. Operators compare parts against them.	Write an SOP for every process, starting with the highest-volume and highest-risk ones.
3	As Level 2, plus all processes have written standard operating procedures (SOPs).	Every process has a controlled, current SOP. Supervisors can find it in seconds.	Build a job instruction for every role and set up a trainer certification scheme.
4	As Level 3, plus all roles have job instructions and certified training.	Job instructions are posted at each station. Training records show a certified trainer’s sign-off for each person and job.	Tie improvement closure to document updates. Track time from improvement to updated standard.
5	As Level 4, plus standards are updated (re-standardized) after every improvement.	Revision history shows standards changing as improvements land. Operators can explain the last change and why.	Sustain: audit adherence, review the age of documents, and keep cutting the lag between improvement and re-standardization.

Evidence to look for

Document

• SOP list with owner, revision, and review date for every process.
• Job instructions with important steps, key points, and reasons.
• Boundary sample register: what, where, approved by, replacement date.
• Training and certification records linked to the skills matrix.
• Improvement records showing which documents were updated.

Observation

• Pick three stations. Is the instruction posted, current, and matching what the operator is actually doing?
• Are boundary samples at the check point, labeled, and in good condition?
• Watch two operators on the same job. Do they follow the same sequence?

Statement (questions to ask and who to ask)

• Operators: “Show me how you know this part is good.” “When did this instruction last change, and why?”
• Team leaders: “How do you check people are following the standard?” “Who can certify a new operator?”
• Engineers: “When you finish an improvement, what happens to the documents?”

Management report

• Percent of processes with current SOPs and percent of roles with job instructions.
• Percent of people certified on their assigned jobs.
• Standard work adherence audit results by area.
• Defect escapes traced to non-standard methods.

Common pitfalls

• Writing standards in the office. Engineers write a document nobody on the floor recognizes. Write it at the workstation with the people who do the job.
• Too much text. A 12-page SOP at the station will not be read. Keep procedures short and push the how-to into visual job instructions.
• Treating the standard as fixed. A standard nobody is allowed to improve becomes a standard nobody follows. It should change whenever a better way is proven.
• Training by shadowing only. “Sit with Joe for a week” copies Joe’s shortcuts. Use a structured method and certify.
• Worn or missing boundary samples. Faded, damaged, or undated samples drift the quality standard without anyone noticing.
• No link to improvement. Projects close, the method changes, and the documents stay the same. Within a year the paperwork is fiction.

Template

Job Instruction Sheet

Field	Entry
Job name / station
Part number(s)
Takt time
Standard in-process stock
Tools and PPE
Related SOP (number, revision)
Boundary sample reference
Prepared by / date
Approved by / date

#	Important step (what)	Key points (how: quality, safety, knack)	Reason (why)	Photo ref
1
2
3

Standard Work Adherence Check (team leader, one job per shift)

• [ ] Current instruction posted at the station, revision matches the controlled copy
• [ ] Operator follows the step sequence as written
• [ ] Key points observed (quality, safety)
• [ ] Standard in-process stock at the defined level
• [ ] Boundary samples present, labeled, within replacement date
• [ ] Operator certified on this job (check skills matrix)
• [ ] Any gap logged: retrain, or raise a change to the standard

First 30 days

Week 1: List every process and role. Mark which have an SOP, a job instruction, and boundary samples. Pick one pilot line.

Week 2: Observe the pilot jobs, agree the best method with operators, and draft job instructions. Collect boundary samples for every visual check.

Week 3: Get approvals, post the instructions, and train and certify the pilot team using the four-step method. Start daily adherence checks.

Week 4: Review adherence results and defects. Fix the instructions that did not match reality. Add a “documents updated?” gate to your improvement closure process and plan the rollout to the next area.

Further reading

• Lean Enterprise Institute, Lean Lexicon entry “Standardized Work”: https://www.lean.org/lexicon-terms/standardized-work/
• Lean Enterprise Institute, Lean Lexicon entry “Training Within Industry (TWI)”: https://www.lean.org/lexicon-terms/training-within-industry-twi/
• Donald A. Dinero, Training Within Industry: The Foundation of Lean (Productivity Press, 2005).
• Patrick Graupp and Robert J. Wrona, The TWI Workbook: Essential Skills for Supervisors (Productivity Press, 2006).
• Jeffrey K. Liker, The Toyota Way (McGraw-Hill, 2004), Principle 6 on standardized tasks.