Kaizen Event

Goal

A kaizen event is a time-boxed improvement session: a cross-functional team sets aside most of its routine tasks for one to seven days to change a specific process. The US Environmental Protection Agency (EPA) observes that the team often implements the chosen improvements within 72 hours of the start of the event.

The event settles one question: which changes to this process should be adopted, among those the team can test on site? The EPA states that the team favours solutions without major investment. Anything that needs a budget, IT development or a third party's agreement falls outside the event and goes to management.

The team delivers the changed process, its written standard and the before-and-after measurements. It reports its results to management at the end of the event, as the Lean Enterprise Institute (LEI) describes. It leaves a list of open actions, each with an owner and a due date, and tracks them until the last check.

Usage

When to use it

• Bottleneck, delay or backlog on a clearly scoped process: the EPA lists them among the targets of an event.
• Quality below customer expectations in a specific area: returns, data-entry errors or scrap can be measured before and after.
• Area marked with a kaizen burst on a value stream map: the burst flags an area to address, which becomes a candidate event.
• Administrative process as well as production: the EPA cites both; an approval workflow changes the same way as a production line.
• Change within the team's reach: order of steps, forms, internal rules, workstation layout, without major investment.
• People who do the work can be released for several days: the team must be at the gemba, full-time or close to it.
• A manager ready to hear staff contradict them: the analysis rests on what the people who do the work see.

When not to use it

• Unstable process, with no standard and frequent breakdowns or absences: stabilise it first, through maintenance, staff attendance and written standard work.
• Solution that requires investment or several months of development: open a project with a project charter and a business case.
• Improvement expected every day, in small steps: set up a routine such as Toyota kata rather than a series of events.

Description

The EPA divides the event into three phases: prepare, run the event, follow up. It adds that each organisation adapts and reorders these activities. The LEI describes how a typical one-week event runs. Participants learn the approach and the Lean principles relevant to the problem, go to the gemba to see actual conditions, then change the process and test it. They then standardise the process and report the results to management. Both descriptions follow the same order.

Preparing the event

The process owner and the sponsor, the member of management who backs the event, first choose the area. The EPA's list of targets includes an area where work in progress piles up, an administrative or production process with bottlenecks or delays, an area whose quality falls short of customer expectations or an activity with a high financial impact. Within that area, owner and sponsor pick a specific problem: cut a lead time, improve quality, raise throughput.

They write a one-page charter, for instance for a fictitious event on the supplier-invoice process of a hospital.

A written mandate saves the team from discovering on day three that a tested solution will never be authorised.

The EPA holds that the team should include the people who work in the targeted process. People from outside the process can join to bring a fresh view. The LEI counts experts, consultants, operators and their direct supervisors among the members. Each member knows the approach or is trained in it before day one. The line manager arranges cover for the members before the event.

The team gains a day if the baseline figures are ready before day one: lead times, volumes, errors, system extracts. The EPA has the team collect these figures during the event; collecting them beforehand frees time for the analysis. Logistics are settled beforehand too: a room close to the gemba, access to the systems, the people to call on for the trials.

Running the event

1. Understand the current state. The team goes to the gemba and follows the work from start to finish: a part, an invoice, a case file. To describe the current state, the EPA cites value stream mapping and the five whys. The aim is for every member to see the same problem.
2. Measure. Each member receives a measurement task. In production, the EPA cites quality, scrap and its origin, distances travelled, changeovers, bottlenecks and work in progress. In the office, the team records lead times, handoffs between departments, cases waiting, returns and handling time per case.
3. Spot the waste. The team asks what the purpose of the process is, then whether each step contributes to it. It notes each waste it observes: waiting, handoff, double entry, redundant check, rework.
4. Search and test. The team looks for solutions through brainstorming, then tests them on site or on a mock-up of the process. In the office, the team runs twenty real cases through the new sequence. It keeps the solutions that hold up in the trial and puts them in place.
5. Measure the new state. According to the EPA, the team records the new cycle times and quantifies the gains. Some gains show during the event, such as handling time. Others, such as an end-to-end lead time, can be measured only after a few weeks.
6. Standardise. Taiichi Ohno, the creator of the Toyota Production System, said that there is no kaizen without a standard, the LEI reports. The people who do the work write the standard: the order of steps, who does what, the expected time, the checks the process keeps. The process owner becomes its owner.
7. Report the results. The team presents the before-and-after measurements, the standard, the open actions and the dates of the checks to management. Management decides on the items that fell outside the mandate.

A five-day split

None of the sources cited sets a day-by-day split. The team compresses or stretches the customary split of a five-day event to the length it has chosen.

Following up at 30 and 90 days

After the event, the team tracks the charter's metrics to document the gain. The EPA mentions follow-up sessions, sometimes held 30 and 90 days after the event, to assess performance and decide on adjustments. The people who work in the process give their view at these sessions. According to the EPA, results are often posted on a board that everyone can see. Open actions are tracked the same way, for example on a kaizen board: each action appears with its owner and status.

At 30 days, the check catches a slide back to the old routine while it is still recent. At 90 days, it verifies that the gain has held. Without follow-up, according to the LEI, the gains of the event are soon lost, because staff and managers return to their old way of working. The process owner therefore runs the checks, and the event team comes back for them.

Each check compares the metrics with their targets and reviews the actions that are due or overdue. The process owner also goes back to the gemba to verify that the standard is applied. A standard that nobody follows signals the return to the old process before the metrics show it.

Common mistakes

Counting events. The LEI names this failure mode: the metric tracked becomes the number of events held, in place of the results of the process. An organisation that announces twenty events a year says nothing about its lead times.

Handing the event to experts. The LEI names two related failures: management does not involve the people who do the work, or engineers removed from daily work lead the improvement in place of managers and operators. The standard that results has no owner at the gemba.

Launching the event on an unstable process. The LEI asks management to establish stable operations first: machines run, people are present, tasks repeat. On an unstable process, the team cannot tell whether a measured gap comes from its change or from chance.

Taking too wide a scope. An entire value stream cannot be changed in a week. The team spends the event mapping and tries nothing. That is why the charter sets a first and a last step.

Calling members back to their jobs. A member who leaves every afternoon to deal with urgent work misses the trials. Cover arranged beforehand settles this.

Removing a control without checking what it was for. The EPA warns that an event can produce changes that run against environmental requirements. It recommends consulting the staff in charge of environmental matters. The same risk applies to occupational safety, data protection and the internal control system (ICS). An approval judged redundant may be the control that the statutory auditor expects: in an ordinary audit, the auditor checks whether an ICS exists. Before removing an approval or a control, the team asks its owner what it covers. The charter names these owners.

Boundaries with neighbouring methods

A workshop brings stakeholders together to produce a decision or a document. A kaizen event changes the process during the session and measures it.

Value stream mapping draws an entire value stream and marks the areas to address on the map with kaizen bursts. Each burst can become an event. Within the event, the team maps the targeted segment.

A gemba walk takes a manager to the place where the work is done to observe and ask questions, without changing the process during the walk. The event goes to the gemba to change what it sees there. An event can apply 5S, a method that sorts a workstation and keeps it in order, when a disordered workstation causes the waste.

The LEI notes that events build skills, but that management must not rely on them alone. Daily improvement requires managers to develop problem-solving close to the work. Toyota kata is one routine for it. The event deals with a one-off problem; the kata sustains improvement day after day.

AI considerations

Before the event, an assistant prepares the baseline figures. It extracts lead times, volumes, rework loops and the steps where cases wait from the logs of an ERP or a ticketing tool. The team checks the extract against a few cases traced by hand: a timestamp that matches no real step distorts the baseline. The assistant can also draft a first version of the charter from the sponsor's request.

During the event, it cleans up the current-state map photographed on the wall, the list of waste and the observation notes. At the end, it drafts the standard and the presentation from the team's decisions. Since the team works in French, the assistant translates both into German for a site in German-speaking Switzerland. The team rereads each step of the standard: a step left out becomes a gap at the first check.

An assistant that proposes solutions from the data alone replaces what the event goes to the gemba to find: what the people who do the work see. It produces plausible solutions that nobody in the room defends.

The event measures the process. A handling time per person, drawn from a system's logs, measures employees. The team records times per step and per case, without linking them to an employee.

Examples

A fictitious five-day event targets the supplier-invoice process of a regional hospital in French-speaking Switzerland. The table tracks its metrics before the event, at its end, at day 30 and at day 90.

At the day-30 check, three metrics miss their target: the lead time, the invoices awaiting approval and the lost discounts. The team finds the cause: four departments, radiology among them, still approve invoices on paper. The head of accounts payable has the IT security officer open electronic approval to the heads of these four departments, due by day 45. At the day-90 check, all three metrics are within target.

The end-to-end lead time and the lost discounts have no value at the end of the event. They can be read only once invoices have passed through the whole new process. A presentation that puts a figure on them on the Friday has estimated them.

Visualisations

The three-phase diagram places the event between its preparation and its follow-up, with the checks at 30 and 90 days on the timeline. It shows that the days of the event are only its central part. On one page, the charter sets out the team's mandate and what lies beyond its reach. The five-day split states what the team has in hand each evening. The follow-up table shows the gap found at day 30 and its correction by day 90.

Cost

Tooling

An event needs little equipment: brown paper and sticky notes for the current-state map, a stopwatch for the times, a spreadsheet for the measurements. An online whiteboard replaces the wall when part of the team works remotely, but the gemba is visited on site.

For an administrative process, the logs of an ERP or a ticketing tool supply the baseline lead times. Process mining software reconstructs the actual process from those logs and pays off when the process handles thousands of cases a month. It shows where cases wait. The cause of the wait is seen at the gemba.

Follow-up fits on a board posted in the area, physical or electronic, that carries the metrics and the open actions. The presentation of results often fits on one A3 sheet.

Sources

• U.S. Environmental Protection Agency, Lean Thinking and Methods: Kaizen: the three phases of the event, its length of one to seven days, the choice of target, the team's composition, implementation within 72 hours, follow-up at 30 and 90 days and the environmental risk.
• Lean Enterprise Institute, Kaizen: A Resource Guide: the usual length of five days, Imai's introduction of kaizen to the West in 1986, Ohno's words on the standard, prior stability and the failure modes of the event.
• Lean Enterprise Institute, Kaizen Workshop: the team's composition and how a typical event runs, from the gemba visit to the presentation of results to management.
• Imai, Masaaki (2012), Gemba Kaizen: A Commonsense Approach to a Continuous Improvement Strategy, 2nd edition, McGraw-Hill; 1st edition 1997: the book in which Imai, who made the term kaizen known in the West, describes improvement carried out at the gemba.
• Swiss Confederation, Swiss Code of Obligations (CO), SR 220, art. 728a para. 1 no. 3: in an ordinary audit, the statutory auditor checks whether an internal control system exists.