Jishuken

Definition

Jishuken is a hands-on study group activity where managers and engineers go to the shop floor to study, analyze, and improve actual production processes. The distinguishing feature is learning by doing — participants learn TPS not through lectures or classroom training but by applying TPS principles to real problems in a real workplace, under the guidance of an experienced practitioner.

Jishuken combines education and improvement in a single activity. The participants learn TPS methods by using them, and the host company gets genuine process improvements. The learning is embodied in the physical changes made to the shop floor, not in notes or presentations.

Japanese Origin

Jishuken (自主研) is an abbreviation of 自主研究 (jishu kenkyu), combining 自主 (jishu, “self-directed” or “voluntary”) with 研究 (kenkyu, “study” or “research”). The full meaning is “voluntary self-study” or “autonomous research.” The term reflects the expectation that learning is active and self-motivated — participants are not passively taught but actively investigate and discover through their own effort.

History at Toyota

Founding of the Jishu Kenkyukai (October 1976)

The formal jishuken activity — properly called the Jishu Kenkyukai (自主研究会, “Voluntary Study Group”) — was founded in October 1976 by Toyota’s Production Research Division (生産調査室, Seisan Chosashitsu), the internal group later known in English as OMCD. See the separate entry on OMCD for the organizational history of that group.

The Jishu Kenkyukai had a distinctive character. It was not Toyota employment — the activity was literally “voluntary self-study” conducted outside normal company duties. Early members participated as individuals, not as official company representatives. However, members were selected from the Kyohokai (協豊会) and Kanto Kyohokai (関東協豊会) — Toyota’s cooperative supplier associations — giving the activity a semi-corporate character. The founding is recorded in the Toyota 50-Year History under 1976.

The first members were 17 people from 17 cooperating companies, plus Toyota’s Production Research Division. Taiichi Ohno was not a member — he supported the activity as an advisor and consultant (顧問).

Original Members

Starting in October 1976, the OMCD office of Toyota initiated structured introduction and implementation of TPS and kaizen concepts into the Tier One supply base. Jishuken activities were initiated at 17 different companies. Each participating company designated a key person in charge of organizing the workshops at that site and promoting the learning points.

The original 17 companies and their designated jishuken support persons were:

Toyota Motor Corporation support personnel included Kikuo Suzumura and Fujio Cho. Taiichi Ohno never personally led any of the jishuken workshops at suppliers; however, he acted as an advisor, speaking to participants and providing feedback on implementation. Nampachi Hayashi was a key contributor in the latter period of OMCD’s jishuken work.

The First Sessions

The first session was held November 16, 1976 at Nippon Denso’s Anjo plant. The theme was experiments with no-work-in-process flow control on a parts machining line and cycle time setting — including how to determine standard waiting time per process and standard time setting. At this first session, Ohno gave a speech emphasizing that the Toyota Production System should not be reduced to just kanban — it is a step toward a general production method for all manufacturing.

The second and third sessions were held December 16 and 24, 1976 at Taiho Kogyo and Nittetsu Valve respectively. The follow-up (fourth session) was January 25, 1977.

Structure and Operating Method

The Jishu Kenkyukai met in principle once per month, with companies taking turns hosting. The host company’s shop floor problems became the improvement theme. The activity consisted of four parts:

1. Theme establishment — an improvement problem from the host company’s shop floor is raised as the theme
2. Improvement by a cross-company team — members from other companies join the improvement team, working within a set time period to study and trial countermeasures
3. Trial-and-error implementation — improvement measures are trialled and their results presented to all members for review
4. Evaluation by the Production Research Division — critical comments and assessment from Toyota’s OMCD department

If expected results could not be achieved within the limited timeframe, follow-up sessions on the same theme were conducted. The focus was always on practical improvement results, not desk-based discussion.

A Unique Form of Learning

The Jishu Kenkyukai was unprecedented as an educational system. It was not OJT (on-the-job training). It was not Off-JT (classroom training). It was not an academic knowledge-exchange society. The activity took real problems from the host company’s shop floor, but the improvements were abstracted into general principles applicable to any manufacturing environment — what the source literature describes as a “pseudo-genba” (擬似現場) approach: problems raised from the actual shop floor but solved in a way that yields transferable general principles.

The comparison to Harvard Business School case studies is instructive: HBS is famous for its case method, but there are questions about how far case-based diagnosis extends beyond identifying problems toward actually resolving them. The Jishu Kenkyukai went further — it took real problems from participating companies, analyzed their difficulties, practiced improvement, and confirmed results on the shop floor. This research-and-education system was described by Satake Hiroaki as having no equivalent anywhere in the world.

A key operating feature was that each company’s shop floor improvement themes were studied not just by that company’s own employees but by employees from other companies as well. This cross-company participation simultaneously developed improvement capability in the participating members and delivered real improvement results at the host company.

Growth and Evolution

The Jishu Kenkyukai continued on both tracks: within Toyota’s own plants across departments, and as a TPS study group for supplier company representatives. The supplier-facing activity grew substantially — by 1997, 44 companies participated in 6 groups (A through F).

Over time, the participation model shifted: while originally members attended as individuals, participants later attended as company representatives in an official capacity. Some of the original Jishu Kenkyukai members later joined Suzumura’s NPS Kenkyukai — a separate study group he organized that worked with approximately 40 companies on improvement activities.

Jishuken’s Legacy Outside Toyota

Some of the designated key persons who trained under OMCD personnel later retired from their supplier companies and became well-known consultants — notably Yoshiki Iwata (Toyoda Gosei) and Chihiro Nakao (Taiho Kogyo), who founded a consulting company called Shingijutsu in Japan in the late 1980s and then worked in the United States in the early 1990s. Although instrumental in helping establish improvement activities at their own Tier One supplier companies, none of these individuals played any role in the development of the kaizen methodology or overall production system inside Toyota Motor Corporation.

The five-day workshop model of kaizen frequently practiced in North America and other parts of the world since the late 1980s is loosely based on the learning points that individuals such as Iwata and Nakao took from Toyota’s jishuken events. This five-day format was adapted and marketed by consulting firms such as Shingijutsu and TBM (Time Based Management) as a package for introducing lean concepts to overseas companies.

How It Works

Typical structure:

• A group of 5-15 managers/engineers, often from different companies in a supplier group
• A host plant that provides the production area to be studied and improved
• A Toyota sensei or experienced TPS practitioner who guides the activity
• Duration of 3-5 days of intensive shop floor work

The process:

1. Observation — The group goes to the shop floor and observes the current state of a specific production area. They time operations, draw spaghetti diagrams, count inventory, and document the current process.
2. Analysis — Working from their observations (not from reports or data systems), the group identifies waste, imbalances, and opportunities for improvement. The sensei guides their observation and challenges them to see deeper.
3. Improvement — The group develops and implements changes — rearranging equipment, redesigning work sequences, reducing WIP, improving flow. Changes are physical and immediate, not recommendations for future action.
4. Standardization — New standard work is created for the improved process, operators are trained, and visual controls are established.
5. Reflection — The group presents their results and discusses what they learned — both about the specific process and about TPS principles more broadly.

Key characteristics:

• Work happens on the shop floor, not in a conference room
• Changes are implemented during the activity, not planned for later
• The sensei teaches by asking questions and challenging assumptions, not by lecturing
• Participants learn by doing, making mistakes, and being corrected

Common Mistakes

Turning jishuken into classroom training. If participants spend most of their time in presentations and discussions rather than on the shop floor observing, measuring, and changing, it is not jishuken. The entire point is learning through hands-on practice.

No experienced guide. Jishuken without a knowledgeable sensei degrades into well-intentioned but unfocused activity. The sensei provides the TPS lens that helps participants see waste they would otherwise miss, and prevents “improvements” that violate TPS principles.

Making changes without standardizing. Improvements that are not captured in updated standard work and visual controls will revert within days or weeks. The standardization step is what makes jishuken results stick.

Treating jishuken as a one-time event. Jishuken is most powerful as a recurring practice — the same group meets regularly at rotating host sites, building capability over time. A single event produces some improvement; a sustained practice builds deep TPS capability across an organization.