Standard Work: The Baseline That Makes Improvement Possible

"Standard work" sounds like the opposite of improvement. It conjures binders of procedures, rigid rules and people told to stop thinking. In lean practice it means almost the reverse: a short, current description of the best way the team knows to do a job today, written so that tomorrow's better way has something to beat.

The Lean Enterprise Institute (LEI) passes along an observation attributed to Taiichi Ohno, who, in Toyota's own account, helped establish the Toyota Production System: "There can be no kaizen without a standard." Toyota veteran John Shook, writing for LEI, adds the other half that people quote less often: "there is no maintenance of standards without kaizen."

This guide explains what standard work is, why it has to come before improvement, how a small team can write its first standards, and how to keep them from turning into the binder nobody reads.

What Standard Work Means

LEI defines standardized work as precise procedures for each operator's work in a process, built on three elements:

• Takt time: the rate at which work must be completed to meet customer demand. LEI calculates it as available time divided by demand; if a factory runs 480 minutes a day and customers want 240 units, takt time is two minutes.
• The work sequence: the precise order in which a person performs tasks within that time.
• Standard inventory: the amount of work in process, including items in machines, needed to keep the process running smoothly.

Those terms come from production, but they translate. For a small office team, the questions become: how often does this job need to be done to keep up with demand, what is the best-known order of steps, and what materials or information must be on hand for the job to flow?

LEI lists the benefits as documentation of the current process for all shifts, reduced variability, easier training of new people, fewer injuries and less strain, and a baseline for improvement activities.

Why a Standard Comes Before Improvement

If five people do the same job five different ways, a change that helps one of them tells you little. You can't tell whether a result came from the change or from who happened to be working. A standard turns the job into something you can test.

LEI adds an important condition: the process should be reasonably stable first. Its kaizen entry describes this as machines working, workers present, jobs repeatable with quality and material available. Without that, it says, teams "perform kaizen on top of chaos," and gains quickly vanish. Once a stable baseline exists, leaders can set targets against it, and when a team achieves a measurable gain, it updates the standard so the gain doesn't disappear.

That last step is the link to the Plan-Do-Check-Act cycle. LEI's PDCA entry describes the "Act" stage as standardizing the new method by updating the standardized work.

Standard Work Is Not the Same as Every Document

LEI distinguishes standardized work from two related documents:

• A work standards sheet summarizes the requirements a job must meet, such as specifications that assure quality.
• A job instruction sheet, also called a job breakdown sheet, is used to train new people. It lists the steps and any special knack needed to do the job safely and well.

The job breakdown comes from Training Within Industry (TWI), a set of programs developed in the United States during World War II to train large numbers of new workers quickly. According to LEI, TWI faded in the U.S. after the war but was adopted by Japanese companies, including Toyota, and its Job Instruction program is still the primary training tool used by Toyota's team leaders worldwide. A TWI job breakdown sheet has three columns: Important Steps, Key Points and Reasons Why. Job Instruction itself has four steps: prepare the worker, present the job, try out the job and follow up.

For a small team, the practical lesson is to keep these separate. The standard says what the best-known method is. The training sheet helps someone learn it. The requirements say what the result must meet.

Writing Your First Standard

Imagine a hypothetical three-person bookkeeping team whose month-end close takes anywhere from two to five days, depending on who runs it.

1. Go and watch. LEI notes that standardized work "cannot be written at a desk in the engineering office"; it has to be defined at the place where the work is done. Sit with each person during a close and note what they actually do.
2. Pick the best current method. Compare the approaches and agree on the sequence that works best now, borrowing the good ideas from each person.
3. Write it short. One page is a good target: the steps in order, the key point for each step and the reason it matters. Note what must be ready before starting, such as bank statements downloaded and receipts submitted.
4. Note the timing. Record how long each step usually takes, so delays stand out.
5. Put it where the work happens. LEI notes that standardized work charts are often displayed at workstations as a tool for visual management and kaizen. For office work, that might mean pinning it at the top of the shared checklist.
6. Treat it as version one. Date it, and expect to change it.

Keeping Standards Alive

LEI's definition says that once standardized work is established and displayed, it becomes the object of continuous improvement through kaizen. It also says the standard forms are used by supervisors to design the process and by operators to improve their own jobs. Standards should be written and revised with the people who do the work, not handed to them.

Some habits help:

• When someone finds a better way, test it, and if it works, update the page that same week.
• Review the standard whenever results drift, before blaming individuals.
• Retire steps that no longer add value rather than piling on new ones.
• Keep the old version so you can compare.

Shook's LEI article describes the balance as a teeter-totter: you need both stable standards and steady improvement, but most of the time one will outweigh the other. He recalls that at NUMMI, the former GM plant in Fremont, Toyota stressed kaizen with experienced auto workers, while at its Kentucky plant, where most new hires had never worked in the industry, the first order of business was learning to perform a factory job to a basic standard. Your team's starting point decides which side needs weight first.

Common Mistakes

• Writing the ideal process instead of the real best practice.
• Making standards so long that nobody reads them.
• Having a manager or specialist write them alone.
• Using the standard to police people rather than to find problems.
• Never updating it, so it quietly becomes fiction.

Key takeaways

• Standard work is the current best-known method, written down so it can be improved.
• LEI builds it on three elements: takt time, work sequence and standard work in process.
• Stabilize the process first; improvement on top of chaos doesn't hold.
• Write standards where the work happens, with the people who do it, and keep them short.
• When an experiment succeeds, update the standard; that's how gains stick.

Sources

• Lean Enterprise Institute, Standardized Work (Lean Lexicon)
• Lean Enterprise Institute, Kaizen (Lean Lexicon)
• Lean Enterprise Institute, Takt Time (Lean Lexicon)
• Lean Enterprise Institute, Plan, Do, Check, Act (PDCA) (Lean Lexicon)
• Lean Enterprise Institute, Gemba (Lean Lexicon)
• Lean Enterprise Institute, Training Within Industry (TWI) (Lean Lexicon)
• Toyota Motor Corporation, Toyota Production System
• John Shook, Standardized Work or Kaizen? Yes (Lean Enterprise Institute, December 12, 2018)