The flow is one of the most important concepts in understanding Kaizen, since there is always a flow of processes in all types of businesses providing products or services to customers.Looking at the flow provides us with crucial keys for KAIZEN.Take, for example, production systems, which can be classified into two major types: traditional system and just-in-time system.
Traditional SystemIn the former type, the planning department in the corporate office makes production plans based on sales forecast and issues production orders to the plant, which are converted into daily production schedules and forwarded to each process within the plant for execution.The shortcoming of this system is that the sales forecast never turns out to be correct.Sales people are afraid of having no products to sell when orders are received and, consequently, their forecast tends to be on the optimistic side, and production started on this basis inevitably leads to excess inventory.The problem is that, even to this day, majority of manufacturing companies subscribe to this system.It might be said that these companies are in the gambling business since they bet the future of the company on the most unreliable information.Many problems faced by today’s manufacturing companies are derived from this fact, and their problems are mostly intrinsic to the system they subscribe to, namely, traditional system.
Under the traditional system, it is difficult to devise a smooth flow, because production plans are made on forecast which is often untrue, and the plans are subject to change, thus, disrupting the smooth flow. Since batch production is employed in the traditional method, it is another reason why the flow is disrupted between processes.In other words, the traditional system is plagued with an intrinsic shortcoming of disrupted flows. Whenever the flow is disrupted, inventory is accumulated. The quality suffers. Delivery commitment to customers is not fulfilled. This leads to require far more managerial and administrative procedures, interventions and documentations (commonly called as indirect work) and these activities are often carried out in the corporate office far removed from Gemba.These interventions include such activities as production planning, production instructions, instruction of production changes, checking the level of inventory, logistics between processes, warehousing and many more. Further, it leads to require managers or persons to work on these “indirect” assignments at each process.Just –in-timeIn just-in-time production, on the other hand, all activities are triggered from the most reliable information.....customer orders,In the final and ideal stage of JIT , customer orders are forwarded directly to the final production process, namely, assembly process. Based on this information, the last process (assembling process) produces as many number of products as have been ordered, and ship them to the customer directly from the plant, without going through the warehouse. In the meantime, the information on the products assembled in the final process is fed back to each previous process through such means as one-piece-flow and KANBAN. Thus, the information which was started from the customer is forwarded throughout the entire processes, until it reaches the first process of production, namely, purchasing of raw materials and supplies.Take, for example, the case of purchasing of parts and components. Again, in the ideal form of JIT, the role of purchasing is to place orders only as many as have been consumed in the downstream processes, instead of placing orders in big volume, in advance, based on forecast. This is a natural outcome of the reverse flow of “pull” information which started from the customers. Thus, there is a long flow of information starting from customers and going through various processes, and finally, reaching purchasing , and suppliers.
Thus, the flow of information is much simplified in the case of JIT, making the job of managing the entire processes very easy, since one only has to look at the flow and take actions whenever the flow is disrupted. Taiichi Ohno, who was a driving force in developing Toyota production system at Toyota, once said that in JIT system, the “flow” manages the processes, while in the traditional system, management must manage the processes.The core activities of building JIT system is to engage in never-ending KAIZEN activities to make, shorten and minimize the flow, and as a result, to reduce the total lead time. Under this system, the first step is to review all the processes and try to make a flow by connecting separated processes. Once the processes are put together, the next step is to shorten the flow, and minimize the lead time.
Thus, in KAIZEN terms, any bottlenecks that disrupt the flow must be dealt with, and solving these bottlenecks are called KAIZEN. KAIZEN is an indispensable means to build JIT system. In short, any company that has subscribed to traditional system needs KAIZEN. Since the concept of “flow” has been virtually non-existent in the traditional system, KAIZEN is needed in almost all spheres of the business including production, must be carried out involving everybody and continually in other words on the daily basis.
Minimizing the flow offers the following advantages:1. It identifies MUDA (non-value-adding activities) of all kinds.2. It identifies unbalances between processes.3. It shortens the lead time of production, and realizes prompt delivery.
4. It reduces inventories of both work-in-processes and finished products.
The following are the conditions for making, shortening and maintaining the flow.
1. Standardization
As the traditional system is disconnected almost at every process, building JIT system comes class to negating and undoing almost every thing has been done in the past.
Every time a new way of doing the job has been established, it must be standardized so that Gemba does not go back to the same old way. There is always a strong tendency for Gemba people to go back to the same old way, to which they feel comfortable most. Even after KAIZEN was made to build a flow, the manager often finds on visiting the site several weeks later, without checking from time to time, everything has gone back to the old way.
This is also partly because they find the new way uncomfortable, and because they feel that what they had been doing was slighted.
Thus, standardizing the new process and making certain that everybody follows the new standards becomes a key factor to stabilize the new procedures.
2. 5S
As was detailed in the book, Gemba KAIZEN, 5S’s, the five steps of housekeeping, are one of the three pillars of Gemba KAIZEN, together with standardization and muda elimination.
From the standpoint of making a flow, 5S’s are absolutely necessary steps. To make a flow, between processes and shorten the distance and minimize the time of transporting materials within the shortest lead time, everything must be at the right place, which is 5S’s.
In case there is a distance between two processes, for materials to be brought to the next process to make a flow, first, the location to place the material in each process must be fixed. The volume of material must be minimized, avoiding a big batch.
An operator working on a work bench should have all the parts placed within arms’s reach for quick handling to shorten the cycle time.
These activities are all 5S’s.
In the contrast of JIT systems, 5S’s are conducted to make a most efficient flow, and the specific locations for all the materials represent the result of 5S’s activities, namely, standardized 5S’S.
3. MUDA elimination
Taiichi Ohno said that elimination of all types of MUDA was the TASK of Toyota Production System. He listed 7 types of MUDA which were commonly observed on the shop floor, but, in a broader sense, we can say that anything and everything that distracts the smooth flow, is MUDA to be eliminated.
4. Visual management
In the course of developing JIT system, many visual tools have been developed in Gemba so that Gemba people can identify abnormality in real time. Many of them have been developed to help Gemba people to recognize abnormality and take corrective actions in real time and on the spot.
When a total flow has been established, connecting all the processes in the plant, a manager in charge only needs to manage the flow, and Gemba workers are also empowered to maintain the flow. Visual management is the means by which Gemba people, both the manager and workers, assume the responsibility of making the products away from those who are managing Gemba from an isolated office.
5. Recognizing management structure
Once a flow has been established, the relations between production Gemba and other functions such as sales & marketing, physical distribution production planning, production instructions, engineering, quality, industrial engineering, R&D, purchasing, Human Resource Development and Finance go through profound changes.
The responsibility of production falls on the line management, and the roles of other functions are to serve the line. Where Gemba used to be regarded as a problem-child, where thins go wrong, and a good manager would rather not be involved in Gemba affairs. In JIT system, Gemba emerges assume all the necessary responsibilities and accountabilities.
For instance, quality used to be regarded as a job of quality professionals, but in the new role, it is the line management’s role to realize quality, and line management requests the assistance from quality.
In industrial engineering too, Gemba often comes up with a new idea and requests industrial engineering to cope with it.
For instance, Gemba may decide to install a low-cost, small equipment to be installed on the dedicated line for a slow-moving product. The engineering, then starts designing such equipment based on Gemba’s requirements.
On the other hand, once a flow is established, we only have to watch the flow, because the flow manages the processes as Ohno has said.When a flow is established and shortened, only one manager in charge is needed to oversee the entire flow of a particular line or product, and make certain that the flow is running smoothly without disruptions. In effect, JIT not only creates lean production system but also lean management system.In this case, the manager and workers in charge of the flow in Gemba become star players of the game, and are motivated to perform their tasks because they are in direct contact with the customer’s daily requirements and the situations in Gemba, and are empowered to manage them.
As the Gemba people begin to share more responsibilities, the management structure that hitherto has supported traditional system must undergo profound transformation.
Top management is required to review its management system and cross-functional activities with Gemba management in the center.
This is the reason why I believe that we should be using the term JIT management system, rather than JIT production system.
Last but not least, a few words on 5S and visual management. What are the purposes of these activities? My interpretation is that these activities are required in order to make, shorten and minimize the flow, and bring the managerial hegemony to Gemba. No matter how hard one may work to clean the work place with 5S, it is useless unless it leads to shorten the flow.
To sum up, the following shows the difference between the two systems.
Traditional Just-in-time
Production is based on forecast. Production is based on firm orders.
Changing plans is difficult in Gemba. Changing plans is easy in Gemba.
Production plans are dictated by Production plans are dictated by
corporate planning. customer orders.
Managing the flow is complex and The flow is simple and managed by
time consuming. the manager and employees in Gemba.
It requires much managerial and Decision is made in real-time and on the
administrative interventions to Gemba spot in Gemba.
by people who are physically and Gemba managers and employees are
mentally isolated. responsible for managing the entire
flow on their own.
