Information & Training. | Lean Manufacturing. Just In Time Processing.
Just in Time Manufacturing
IntroductionJust-in-time (JIT) is an approach to manufacturing which aims to increase “value-add” activity and eliminate waste by providing the environment to simplify and perfect processes within an organization. Just-in-time manufacturing means producing the necessary items, in the required quantities at the appropriate time.
JIT can deliver significant improvements in operating efficiency. Having raw materials arrive at a manufacturing facility, just in time to enter the production process allows an organization to minimize the amount of inventory it must hold and store. It also minimizes the potential cost of obsolescence, which can arise due to change in product specifications, customer demands, etc..
Putting the JIT concept into practice means a reversal of traditional thinking with regard to managing a manufacturing process flow. In conventional production processes, units are transported to the next production stage as soon as they are ready. In JIT, each stage in the production process looks back to the previous stage to pick up the exact number of units needed. Product (and services) are pulled through the process driven by demand from customers, rather than the traditional approach where product and services are pushed forward based on planned schedules.
The benefits associated with Just In Time Manufacturing.While the prevailing view of JIT is that of an inventory control system, it is much more. JIT is an operational philosophy which can deliver a broad range of benefits.
Examples of the benefits associated with implementing a JIT process:
– The production of high quality, high reliability products that customers want, resulting is satisfied and loyal customers.
– The delivery of products which match the rate that the customers requires.
– Optimized manufacturing process lead-times.
– Minimized and eliminated waste of labour, material and equipment.
– All activity having a defined purpose towards meeting customer needs.
– Continuous reductions in process and equipment set-up and change-over times.
– The elimination of unnecessary inventory and improved inventory management and control.
– Continuous reductions in supplier lead times.
– Ongoing significant improvements in organizational productivity and efficiency.
Is JIT applicable only to Manufacturing ?The concepts of Just In Time are applied to all value creating organizations. While JIT originated in manufacturing in Toyota and Ford, the concepts, principles, approaches and benefits are equally applicable to all industries. In fact many of the JIT benefits achieved in manufacturing environments, arise due to JIT implementation, in the support and back-off services, purchasing, human resources, customer services, etc..
JIT Manufacturing. Definition.“Just-In-Time” is a management and organization philosophy, directed towards the production of goods and services exactly when needed, not before they are needed so that they wait as inventory, not after they are needed, so that it is the customers who have to wait..
JIT can be defined as:
“JIT aims to meet demand simultaneously, with perfect quality and no waste” (Voss)
JIT versus a more traditional approach to organizational management.On a daily basis in every organization there is a need to manage:
The levels of WIP (work in progress),
To implement work arounds due to defective deliveries,
Manage machine downtime,
Manage unstable demand,
Schedule unplanned rework,
Respond to inaccurate quantities,
Train staff where errors are identified,
Schedule production flows,
The presence of inventory through the process allows managers to work around the daily tasks and problems, while decisions can be made and problems addressed. When a problem arises, e.g. a process or equipment failure, the problem is addressed and work continues till the next problem. The majority of problem are not seen as major issues, as they become part of daily work life. Many times the solutions implemented are just short term fixes.
In a JIT environment, the process “STOPS”, when problems arise. JIT exposes any productivity problems, delays, process failures, etc. and as there is no buffer inventory, forces immediate and permanent solutions so that the problems do not re-appear.
Under JIT, a process or equipment failure becomes a major failure. The result is an immediate focus by technical, supervisory and management staff to identify and implement a solution. Due to the major organizational focus on the problem, a permanent solution is demanded, in order to ensure there is no repeat. As JIT gets implemented throughout an organization, problems are permanently addressed and disappear.
Characteristics and objectives of a JIT strategy.Implementing or integrating JIT into any manufacturing or service orientated organization is not an easy decision. It must be planned very cautiously. Implementing JIT takes time and commitment from all levels in the organization. A key objective of JIT is to limit the consumption of resources with a view of optimize efficiency.
When JIT was first developed (within the Toyota Motor Corporation) they categorized waste into the following seven generic formats:
– Overproduction (waste from producing more automobiles than was needed).
– Transportation (waste associated with un-necessarily moving items around a factory due to poor or complex layouts).
– Processing (waste associated with spending more time, effort and resources than was necessary processing products beyond what was necessary or demanded by the customer).
– Time spent Waiting (waste associated with an employee or a machine being idle)
– Inventory (waste associated with keeping stocks of in-process materials or finished automobiles waiting to be shipped to dealerships or customers).
– Defects (waste associated with defective components, defective materials).
– Waste associated with unnecessary Motion. (This is different to transportation. Motion is looking at the efforts and time expended by employees on performing their tasks.).
When an organization is seeking to implement a JIT process, the critical areas of focus will be as follows:
Customer requirements: Understand customer requirements at every stage throughout the process and ensure that product and process specifications match customer expectations.
Process Optimization: Each step of every process will be examined to identify the value add, non-value activities and to ensure process flows are structured to optimize operational efficiency.
Defect elimination: The achievement of defect free outputs. Outputs will apply to every process stage.
Process flexibility: Achieve flexibility in the system. Things will not always go as planned and there needs to be a flexible enough system so that it can be modified easily.
Relationship building. Achieve strong relationship between customers and suppliers. As the JIT philosophy implies virtually no extra stock / inventory, customers, suppliers and the organization itself, need to rely on each other to be flexible, reliable and on time.
Supplier relationships.It is essential that positive, open partnerships are developed between suppliers and manufacturers who work together to remove waste and drive down costs.
Such partnerships will focus on the elimination of unnecessary activities, the elimination of both “in-plant” and “in-transit” inventory, the reduction of lead-time, etc..
Since JIT is a stockless production and does not allow room for defects or error, having trustworthy reliable suppliers is an important factor. Once a reliable supplier is found, creating a good relationship is the next step. This must be a two way relationship providing mutual benefits.
Setup time is an issue that can be investigated with suppliers. Reducing setup time might need redesigning the product or the process.
Once a reduced setup time is achieved the system now can produce smaller batches of products more efficiently. However, this will require deliveries of materials to be more frequent. Finding a supplier closer to the factory or convincing one to relocate closer will also reduce lead time.
Internal considerations in the development of a JIT process.Changing variable production runs towards limited or constant quantity runs is a good start in the process of determining exact resource requirements for “current” production. This knowledge will be required to help measure process improvement results.
Reducing transportation time for individual parts can significantly improve operating efficiency. To achieve this, process flows need to be understood and should be documented. For example re-arranging work stations so they are moved closer together or better aligned with the natural process flow can be a relatively simple solution with consequential efficiency gains. Additionally, correctly structured process flows will help reduce inventory waiting times.
The pro-active use of “down-time” is also another way to help with productivity and efficiency. If an employee is “waiting” there may be opportunities, for example, to perform some form of maintenance on an item of process equipment. This makes the most of the workers time and can help to prevent future breakdowns due to lack of maintenance.
This will require providing employees with more responsibilities and training. This can include training on several items of process or test equipment and an ability to maintain such equipment. The end result will be a more flexible workforce.
Although a kanban system is not specifically required in the implementation of a JIT process, it can be highly effective and provide a structure around the objectives towards inventory reduction.
Lean versus Just-In-Time.There is overlap between Lean and JIT. What are the different areas of focus between Lean and JIT ?
With lean the focus is on:
– Waste reduction (8 types of waste).
– Continuous improvement.
– Employee involvement, actually involvement of all involved (suppliers, customers, employees etc.).
Here the focus is on:
– Driving production based on customer demand.
– Reducing inventory levels (raw materials, work in progress and finished goods) .
– Increasing capacity with existing infrastructure and resources.
– Reducing set-up and change-over times.
– Increasing flexibility.
– Increasing equipment availability through OEE (Overall Equipment Effectiveness), TPM (Total Productive Maintenance), etc..
Lean and JIT
Lean and JIT are complementary and somewhat interchangeable. Given a specific facility, specific equipment, specific employee capabilities, they combine to dramatically increase the overall efficiency of a manufacturing or service operation.
Lean and JIT do not require physical investment, nor major cash injections. They do however require a long term commitment to improvement, a vision proactively pursued by senior management, a building of trust with employees, a building of loyalty with customers and the development of long term mutually beneficial relationships with suppliers.
“Lean” & “Just-In-Time”.
The tools and techniques of Lean & JIT:
– Basic working practices
– Total Productive Maintenance
– Design for manufacture
– Set-up reduction
– Operations focus
– Total staff involvement
– Overall Equipment Effectiveness (OEE)
– Visual management
– Flow layout
– Just-In-Time Supply
– Pull scheduling & Push systems of control
– Kanban control
– 5S method of control
– Levelled scheduling
– Etc. Etc..