Standardized Work Instructions: Sagyo Hyojunsho Template

Your Japanese parent company or customer asks for the sagyo hyojunsho (作業標準書, work standard document) for a process. You send the SOP binder, and the reply comes back: this is not what we mean. Or the opposite happens on your own floor: the work instructions exist, they passed the audit, and nobody opens them. Each shift does the job its own way, and when a defect shows up, nobody can say which step went wrong.

In most plants, the cause is not careless operators. Work instructions go unused when the content no longer matches the real job, when the wording can't be turned into actions, when training is left to whoever is nearby, and when nobody owns revisions. The fix is in how the document is built and kept alive, not in stricter discipline.

This guide sorts out the Japanese terms first: hyojun sagyo (standardized work) vs. sagyo hyojunsho vs. sagyo tejunsho. It then covers the warning signs, the difference between "can't follow" and "won't follow," four layers of root cause, and four fixes. It ends with a work instruction template you can copy, a checklist, and questions to ask your Japanese counterparts.

Contents

1. Hyojun Sagyo vs. Sagyo Hyojunsho vs. Sagyo Tejunsho
2. Signs Your Work Instructions Are Not Being Used
3. "Can't Follow" vs. "Won't Follow"
4. Four Layers of Root Cause
5. Fix 1: Build the Standard From the Best Current Method
6. Fix 2: Write Instructions People Can Follow
7. Fix 3: Teach the Standard and Check It
8. Fix 4: Keep Revisions Moving
9. Where to Start and Common Mistakes
10. Work Instruction Template (Sagyo Hyojunsho Layout)
11. Checklist: Is Your Work Instruction Usable?
12. Questions to Ask Your Japanese Counterparts
13. Limits of This Guide
14. FAQ
15. Sources

Hyojun Sagyo vs. Sagyo Hyojunsho vs. Sagyo Tejunsho

Japanese plants use several similar-sounding terms, and they do not map one-to-one onto "SOP" or "work instruction." The core distinction is between the method and the document:

• Sagyo hyojun (作業標準, work standard) is the agreed way to do a job: the method itself.
• Sagyo hyojunsho (作業標準書, work standard document) is that method written down: the steps and the kyusho (急所, key points), meaning the points where a mistake would break quality or safety. Its purpose is that anyone doing the job finishes it at the same quality and the same safety level.
• Hyojun sagyo (標準作業, standardized work) is the Toyota Production System term. It sets the sequence of the operator's movements to fit the takt time and serves as the baseline for kaizen. See Kaizen in Japanese Companies for its three elements (takt time, work sequence, standard work-in-process).

Depending on the plant, the document may also be called sagyo tejunsho (作業手順書, work procedure), sagyo yoryosho (作業要領書, work guideline), or sagyo shijisho (作業指示書, work instruction). The names differ, but the role is the same: a tool for reproducing the agreed method on the floor.

Japanese term	Literal meaning	Closest English term	What it usually contains
Hyojun sagyo (標準作業)	Standard work	Standardized work (TPS)	Movement sequence fitted to takt time, standard work-in-process
Sagyo hyojun (作業標準)	Work standard	Work standard / standard method	The agreed method itself (not necessarily one document)
Sagyo hyojunsho (作業標準書)	Work standard document	Standardized work instruction / SOP	Steps, key points, reasons, tools, quality checks
Sagyo tejunsho (作業手順書)	Work procedure document	Work instruction / work procedure	Step-by-step procedure, often with safety key points
Sagyo yoryosho / sagyo shijisho (作業要領書／作業指示書)	Work guideline / work instruction	Work instruction	Varies by company

Whatever the name, a work instruction loses its value the moment it drifts from what people actually do. When that happens and a defect appears, you cannot trace where the job left the standard, because root cause analysis and recurrence prevention both need a baseline to compare against.

Signs Your Work Instructions Are Not Being Used

Work instructions rarely fail all at once. They become a formality (keigaika, 形骸化) gradually, and the signs pile up:

Figure 1: Six signs a work instruction has become a formality

If two or more apply, the document is probably no longer working as a tool on the floor.

Never opened during the jobStored far away or too thick to use; nothing leads people to it

Everyone does it differentlySame process, different order or tools on each team or shift

Last revised years agoEquipment and jigs changed; the document did not

New hires are taught by word of mouth"Forget the document, watch how I do it"

Every defect adds another warningMore add-ons and red ink than text; the key points are buried

Tidied up only before auditsLooking right on paper becomes the goal; content drifts from the floor

"Can't Follow" vs. "Won't Follow"

Before choosing a fix, split deviations from the standard into two types. The causes differ, and so do the fixes that work.

Japan's Ministry of Health, Labour and Welfare (MHLW) defines human error as an act that produces an unintended result. Deliberately not doing what should be done, or doing what should not be done, is a violation, and the MHLW treats the two separately.

Figure 2: "Can't follow" errors vs. "won't follow" violations

Both are deviations from the standard, but the causes and the fixes are completely different.

Can't follow (human error)

Won't follow (violation / unsafe act)

Intent

Meant to follow the standard

Knew it was off-standard and changed it anyway

Typical examples

Skipped step, wrong part, untightened bolt, misread instruction

Skipped steps, no PPE, working with a safety device disabled

What you hear

"I slipped up." "I didn't know it said that."

"This much is fine." "Everyone does it." "We can't keep up this way."

Fixes that work

Clearer wording, poka-yoke, confirmation steps, retraining

Time and equipment to do it right, explaining the reasons, revising the procedure itself

Definitions based on the MHLW Workplace Safety Site glossary entries "Human Error" and "Unsafe Acts."

The MHLW describes unsafe acts, the "won't follow" side, as deliberately doing something that can compromise safety, often driven by putting saved effort or time first, by going along because "everyone does it," or by overconfidence built on years of experience. In its 2010 analysis of accident causes, 94.7% of accidents involved both unsafe acts and unsafe conditions, and 1.7% involved unsafe acts alone. Together, unsafe acts played a part in 96.4% of accidents.

The same MHLW guidance says unsafe acts cannot be prevented by attitude alone: weak management and supervision, or defects in equipment and the work environment, often invite them. It also notes accidents where the work standard was never clearly defined, or was defined but not properly taught. If you blame operators' attitude alone, the real causes in the document and the system stay untouched.

Four Layers of Root Cause

Several causes usually overlap. It helps to sort them into four layers: the document, the teaching, the workplace systems, and the organization's stance.

Figure 3: Four layers of why work instructions are not followed

Upper layers are easier to see; lower layers run deeper.

The documentDoesn't match the real job / can't be turned into actions / kept far from the job

Behind it

Teaching"Watch and learn" never passes on key points and reasons / no check after training

Behind it

Revision systemNo revision process or owner

Checking systemNobody checks whether it is followed

Evaluation systemFollowing it or not changes nothing

At the root

Organization's stanceHeavy output pressure; skipping steps gets rewarded

The MHLW lists five kinds of factors that invite unsafe acts (the worker, the work, the work environment, safety management, and the organization) and notes that several usually combine.

The Document Does Not Match the Real Job

This is the most common cause. Production engineering or quality assurance writes the instruction in the office during the production launch. Equipment changes and jig improvements come later, the floor adapts, and the document stays behind. Following it now slows the job down or calls for the wrong tool. Operators are not refusing the standard; following it would stop the work.

The Wording Cannot Be Turned Into Actions

"Tighten securely," "check for abnormalities," and "handle with care" make sense to the writer, but each reader interprets them differently. If the document does not say how tight is secure or what counts as abnormal, operators fill the gap with their own experience. Other common problems:

• Text only, no photos
• Several actions packed into one sentence
• Technical terms and in-house abbreviations with no explanation

For new hires and for operators who read the document's language as a second language, the instruction may simply be unreadable.

Training Is Left to Whoever Is Nearby

If the senior operator who trains a new hire teaches their own way, their way is what spreads, document or not. When people learn the steps but not the reasons, the steps are the first thing dropped on a busy day. Many plants also never check whether the trainee can actually do the job. "I explained it once" is not "they can do it," and the gap shows up later as drift from the standard.

Nothing Changes Whether People Follow It or Not

At the systems layer, the usual causes are:

• No defined revision process and no owner for the document
• Nobody checks whether the standard is followed
• Following it or not makes no difference to how people are evaluated

If operators find a step that is wrong but have nowhere to raise it, they quietly switch to their own method.

The deepest layer is the organization's stance. Where output and delivery pressure are high and people who skip steps to hit the number get credit, no document will be followed. A useful test: can the manager say, "If you followed the standard and fell behind, we treat that as a problem with the standard"?

Fix 1: Build the Standard From the Best Current Method

Start by matching the document's content to the best way the job is done on the floor. A guide to writing work procedures, published by the MHLW as part of its model safety and health rules (written for home-care services, but the method applies to any workplace), lays out six steps from observation to maintenance:

Figure 4: Six steps to building a work procedure

Start from observing the job, not from the office, and treat training and upkeep as part of the same job.

Build

01Understand the jobObserve the real job and map its processes and task groups

02Break down the jobSplit it into major, middle, and minor units and set the scope

03DraftAdd key points for success, safety, and ease; get operators' input

Embed

04ApproveApprove it as the official standard through the approval route

05TrainTrain the operators who do the job and record it

06MaintainReview and revise when methods or tools change

Adapted for manufacturing from the steps in the MHLW work procedure guide (written for home-care services).

Don't Just Copy the Current Method

The same guide warns that adopting a flawed method as the standard makes things worse. Before you write down what you observed, check it for waste, overburden, and unevenness (muda, muri, mura), check the order of steps, and look for steps you can drop.

This is also the stage to capture what skilled operators do well. The tricks veterans use without thinking are prime candidates for key points, and writing them down is what makes the document useful to the people doing the job.

Pick Key Points for Success, Safety, and Ease

If every motion gets a warning, the important ones get lost. Limit key points to three kinds:

• Points that make or break quality
• Points that can lead to injury
• Points that make the job easier

Keep past defect records and near-miss (hiyari hatto) reports next to you while you choose them. If the process has a process FMEA, carry the items it ranks as high priority into the key points so the quality priorities and the work instruction line up.

Let the People Who Do the Job Test the Draft

Have an operator who does the job read the draft and run the job once exactly as written. The writer always thinks the text is clear; a first-time reader always finds a spot that trips them up. When operators help write the document, it stops being paperwork handed down and becomes the method they agreed on. Whether a work instruction gets followed is largely decided at this stage.

Fix 2: Write Instructions People Can Follow

Even correct content will not be followed if readers cannot reproduce the motion. Start by replacing vague words with things the operator can see or measure.

Figure 5: Wording that gets ignored vs. wording that gets followed

Replace words that each reader interprets differently with actions and criteria.

Gets ignored

• Tighten the bolts securely
• Check the appearance for abnormalities
• Handle parts with care
• Set the jig, align it, clamp it, and start machining (several actions in one sentence)
• All cautions listed together at the end

Gets followed

• Tighten to the specified torque with a torque wrench, confirm the click, then apply a torque mark
• Compare with the boundary sample for scratches and dents (photos of accept/reject)
• Pick up one part at a time and place it in a tray slot (no stacking)
• One action per line: "Set jig," "Align," and "Clamp" on separate lines
• Key point and reason written next to the step they belong to

Generic examples. Take actual torque values and acceptance criteria from the drawing and quality standards.

Use Three Columns: Step, Key Point, Reason

Most work instructions that get used are laid out as a table with three columns from left to right: major step, key point, and reason for the key point. Each row holds one action. The key point is what must not be missed within that step, and the reason explains why.

The reason column is the one people skip, but steps with a stated reason are the ones that survive a busy shift. If operators know that the torque mark is there so the next process can spot an untightened bolt at a glance, they can judge the step's purpose for themselves. This three-column layout is the same one TWI calls a job breakdown; see the template below.

Show It With Photos, Not Paragraphs

Part orientation, tool position, and accept/reject samples come across better in one photo than in a paragraph. Putting a good and a bad example side by side and circling the difference cuts reading time sharply.

More plants now film short videos of the job and show them on tablets. Video shows how fast to move and how much force to use, but viewers can't always tell where the key point is, so mark it with captions or still frames.

Write for the People Who Will Read It

Long blocks of text shut out anyone who reads the language slowly. Build pages around photos, add reading aids where needed (in Japan, furigana over kanji), and prepare translated versions in the main languages spoken on the floor. Plants outside Japan face the same issue with documents written in Japanese or English. Simple layouts help native-speaking new hires too.

Put It Where the Work Happens

A document in an office cabinet cannot be checked during the job. Pull out the pages each process needs and post them at eye level at the workstation, or make them available on a terminal. Put a revision number and date on every posted copy, and set a rule to collect old versions after each revision, so the posted copy never differs from the controlled one.

Fix 3: Teach the Standard and Check It

A good document changes nothing until people learn it. The third fix is to make teaching a defined procedure instead of leaving it to individuals.

Use TWI Job Instruction as the Teaching Method

The method many Japanese plants use is TWI (Training Within Industry) Job Instruction (JI). It was developed in the US during World War II and introduced to Japan's Ministry of Labour in 1950. JI standardizes teaching itself into four steps:

Figure 6: The four steps of TWI Job Instruction

Teaching doesn't end with an explanation: have them do it, check it, and keep following up.

STEP 1Prepare the workerPut them at ease, say what the job is and why it matters, and position them to see

STEP 2Present the operationShow the major steps one at a time, stressing each key point

STEP 3Try out performanceHave them do it, correct errors, and have them explain steps, key points, and reasons

STEP 4Follow upName who to ask, check often, and taper off coaching

Step names follow common TWI usage. Wording of the steps and details varies between training providers.

When you combine JI with the work instruction, the key move is in Step 3: have the operator say the key points and their reasons in their own words. That is how the trainer confirms the content actually landed. The step / key point / reason table doubles as the JI training material. For the full method, including how to prepare and when a new hire can work alone, see TWI Job Instruction and OJT in Japanese Plants.

Build Confirmation Into the Steps

To reduce "can't follow" errors, don't rely on attention alone; write confirmation into the procedure as an action. The best-known example is shisa kosho (指差呼称, pointing and calling): point at the target and say its name and state out loud. In a 1994 experiment cited by the MHLW, a button-pressing error rate of 2.38% with neither action fell to 0.38% with both pointing and calling, about one-sixth. Calling alone gave 1.0% and pointing alone 0.75%. More detail is in Kiken Yochi (KY) Training.

The MHLW lists four approaches to preventing human error:

• Train people not to make the mistake
• Make mistakes hard to make
• Make mistakes easy to catch right away
• Keep the impact of a mistake small

Confirmation steps in the document, combined with jigs and poka-yoke that physically block the wrong action, work better than training alone.

Go and Watch the Job

After training, team leaders and supervisors should observe the job regularly and compare it with the document. When they find a gap, they should ask why the job is done this way rather than blame the operator on the spot.

Asking often reveals that the document is out of date or the jig is awkward. If observation is framed as collecting information to fix the document, not as policing, operators tell you what is really going on. Track who can do which process to standard on a skill matrix (rikiryo-hyo, 力量表) so nobody falls through the cracks.

Fix 4: Keep Revisions Moving

The fourth fix is a system that keeps updating the document as the floor changes. Most work instructions go stale because they were right when written and then fell behind.

Figure 8: SDCA keeps the standard; PDCA improves it

Link the loop that runs the standard with the loop that improves it, and always write improvements back into the document.

Maintenance loop: SDCA (keep the standard)

SStandardizeWrite the best current method into the document

DDoWork to the procedure as trained

CCheckSpot gaps from the standard through observation and quality data

AActDecide whether the gap comes from the person or the standard, and act

If the standard is the problem, move to the improvement loop

Improvement loop: PDCA (improve the standard)

PPlanPlan improvements from defects, near misses, and suggestions

DDoTrial on one process or shift

CCheckCheck the change in quality, safety, and work time

AAct (standardize)If it works, revise the document and return to SDCA

An improvement that never reaches the document is lost at the next transfer or new hire.

The Japanese Society for Quality Control's daily management guideline (JSQC-Std 32-001) positions the SDCA cycle as the method of daily management.

Define What Triggers a Revision

"Fix it when someone notices" means nobody fixes it. Decide in advance which events trigger a review, for example:

• A change in equipment, jigs, or materials
• A defect or customer complaint
• A near-miss report
• An improvement suggestion from an operator

Add a scheduled review, such as once a year, so even stable processes do not go stale. If a defect investigation with the seven QC tools or a 5 Whys analysis points to the work method, treat that as a revision trigger too.

Give Operators a Place to Say "This Is Wrong"

Operators need to know whom to tell when they find a problem in the document. One workable flow: the team leader takes the report, decides with production engineering or quality assurance, and revises the document by a set deadline.

When a suggestion is not adopted, tell the operator why. In a workplace where speaking up changes nothing, operators switch silently to their own methods, and that silence is where most ignored work instructions start. The kaizen suggestion system (teian) is one channel Japanese plants use for this.

Revise, Then Retrain

Plants often rewrite the document and never tell the operators. Make it one procedure: issue the new version with the changes marked, retrain the affected operators, even briefly, and record the training.

Digital work instruction systems and generative AI that drafts procedures from photos and video are spreading. They are useful tools, but the plants that get results decide the workflow and who owns what first. Digitizing without a revision system just moves outdated content onto a screen.

Where to Start and Common Mistakes

Trying all four fixes on every process at once is not realistic. Start small and show results; the floor will cooperate more readily.

Start with processes that have many defects or near misses, processes with a high injury risk, and processes that set critical product characteristics. Judge the safety priority against your site's accident record and basic safety management, so it lines up with your other safety measures. Form a small team of the operators, the team leader, and someone from production engineering and quality assurance, and run one full cycle: observe, revise, retrain. Once one process shows fewer defects and less fumbling, it is easier to extend to others.

Three mistakes come up again and again:

• Rewriting every document at once. The workload forces people to write in the office, and you end up with a new batch of documents that do not match the floor.
• Answering non-compliance with penalties and written apologies alone. Violations should not be ignored, but heavier penalties alone push deviations out of sight. Once they stop being reported, you lose the clues you need to fix the document.
• Writing for the audit. A shelf of tidy documents means nothing if operators do not use them. Decide exactly when in the daily routine each document gets opened, such as before the start-of-shift check or during a changeover.

Work Instruction Template (Sagyo Hyojunsho Layout)

Below is a typical layout that combines a header block with the step / key point / reason table. Field names and order vary by company, so treat it as a starting point and match your customer's format if they specify one.

Header block

Field	What to write
Document number / revision / date	Controlled number, revision letter or number, date of this revision
Process / workstation	Process name and station number as on the process flow chart
Product / part number	Applicable models or part numbers
Prepared / checked / approved	Names or stamps (Japanese documents often use three approval boxes)
Tools, jigs, gauges	Tool IDs and settings referenced in the steps
PPE	Required protective equipment for this job
Quality characteristics	Characteristics this process controls, with a reference to the drawing or control plan
Related documents	Drawing, inspection standard, boundary samples
Revision history	What changed, why, and who was retrained

Body: step / key point / reason (fictional example: fitting a pump cover)

No.	Major step (one action)	Key point	Reason	Photo
1	Place the housing in the jig	Port faces the jig's locating pin	Wrong orientation puts the port on the wrong side	Good / bad example
2	Fit the gasket	Check against the boundary sample for no nicks or twists	Damaged gasket causes leaks	Boundary sample photo
3	Fit the cover and run all bolts in by hand	Hand-tight first, all bolts	Prevents cross-threading and cover tilt	—
4	Torque bolts with the torque wrench	Specified torque (see drawing), crisscross order, confirm the click	Uneven torque distorts the seal	Order diagram
5	Apply torque marks	Mark every bolt after torquing	Lets the next process see a missed bolt at a glance	Marked bolt photo

Checklist: Is Your Work Instruction Usable?

• Written from observation of the current best method, not from the office
• One action per row; no "securely," "properly," or "check for abnormalities" without a criterion
• Key points limited to quality, safety, and ease, each with a reason
• Photos of good and bad examples for orientation, tool position, and accept/reject
• Readable by every operator on that station (language, terms, abbreviations)
• Posted at the workstation, with revision number and date matching the controlled copy
• Draft tested by an operator before release
• Trainees can state the key points and reasons in their own words
• Supervisors observe the job regularly and compare it with the document
• Revision triggers, an owner, and a channel for operator feedback are defined
• Every revision is followed by retraining, with a record

Questions to Ask Your Japanese Counterparts

• When you say sagyo hyojunsho, do you mean a step-by-step work instruction, a standardized work chart, or both? Can you share a sample of the format you expect?
• Which processes need a work instruction submitted to you, and which can stay internal?
• Do you require key points and reasons for each step, or photos at a set level of detail?
• Which characteristics or steps do you treat as critical, and must they be marked in the document?
• Which changes require notifying you before we revise the document (for example, a 4M change: man, machine, material, method)?
• What training record do you expect to see after a revision?
• In which language should the document be kept, and is a bilingual version acceptable?

Limits of This Guide

• Document names, layouts, and approval routes differ by company and industry. A customer's own format and requirements take priority.
• The accident statistics and the pointing-and-calling experiment come from Japanese sources (MHLW). Results at your site may differ.
• This guide does not replace safety procedures. Safety-critical steps and legal training requirements follow your site's safety rules and local regulations. In Japan, Article 59 of the Industrial Safety and Health Act and Article 35 of the Ordinance on Industrial Safety and Health require safety and health training, including on work procedures, at hiring and when the job content changes.
• Standardized work in the TPS sense (takt time and movement sequence) is a separate tool covered only briefly here.

FAQ

What Is a Sagyo Hyojunsho?

It is a Japanese work standard document: the agreed method for a job, written down as steps and key points so anyone doing the job reaches the same quality and safety level. In English it is closest to a standardized work instruction or SOP.

What Is the Difference Between Standard Work and a Work Instruction?

Standardized work (hyojun sagyo) in the Toyota Production System fixes the operator's movement sequence to the takt time and serves as the baseline for kaizen. A work instruction (sagyo hyojunsho or sagyo tejunsho) documents how to do the job: steps, key points, and reasons. Many plants use both.

Why Don't Workers Follow Work Instructions?

Usually because the document no longer matches the job, the wording can't be turned into actions, training was left to individuals, or nobody owns revisions. Separate unintended errors ("can't follow") from deliberate shortcuts ("won't follow"); they need different fixes.

What Should a Work Instruction Template Include?

A header with document number, revision, process, tools, PPE, quality characteristics, and approvals, plus a body table with one action per row, the key point, the reason, and a photo. See the template above.

What Is SDCA?

SDCA (Standardize, Do, Check, Act) is the cycle for maintaining a standard. Japanese quality practice pairs it with PDCA: SDCA keeps the current standard running, PDCA improves it, and each improvement is written back into the standard.

Sources

• Unsafe acts and the 2010 accident cause analysis: MHLW Workplace Safety Site, "Unsafe Acts" (Japanese)
• Human error vs. violation, four prevention directions: MHLW Workplace Safety Site, "Human Error" (Japanese)
• Pointing-and-calling experiment: MHLW Workplace Safety Site, "Pointing and Calling" (Japanese)
• Model safety and health rules for home-care services, including the work procedure guide: Fukuoka Labour Bureau, MHLW (Japanese)
• Daily management guideline (SDCA): Japanese Society for Quality Control, JSQC-Std 32-001, adopted as JIS Q 9026, "Performance improvement of management systems — Guidelines for daily management"