Lean management

Management processes are constantly evolving so as to assimlate the new techniques. The evolution of new techniques is in response to the need of having a mean andlean operations which leads to effectiveness, cost saving and efficiency. 

 Lean production, manufacturing or service require half the human effort; half the manufacturing space, half the investment in tools; half the extension hours (cycle time of service). Lean means no fat - no waste, but adopts the zero-waste.

Nature of Lean system

The characteristics of lean manufacturing:

• Continuous flow of production
• No waiting time
• No  inventory
• Continuous finding ways of reducing process time.
• Pull processing

Seven Fundamental Forms of Waste

Overproduction - the making of too much, too early or just in case.

 Waiting - where materials or information are waiting to produce to the next process. They are not moving or having value added.

 Transporting - where materials (or information) are being transported into, out of or around the factory transport cannot be fully eliminated, but the aim is to minimize it.

 Inappropriate processing - using machinery or equipment which is inappropriate in terms of 'capacity' to perform an operation.

 Unnecessary inventory - which ties up capital and space and prevents identification of problems.

Defects -defined in terms of product defects, rework defects, scrap defects or service defects. Technology and Operations Management for Plantation

Unnecessary motion - the ergonomics (efficiency) of the work place

Task Flexibility is a central aspect of lean Production system (Womack et.al., 1990),

Lean System-

• Just-in- time
• Kaizen Costing
• 5 Ss
• Total Productive Maintainance
• Cellular Manufacturing
• Six Sigma

Innovation and Business Process Re-engineering

• Process Innovation
• Business Process Re-engineering

Just-in-time-

Introduction-

Two factors which influence the inventories of all types are: the accuracy and details of the final forecast-all the inventories are geared for future requirements and are therefore sensitive to this factor-and the available storage space-the logical sequence to this factor is the shelf life of the items stored factor for consideration in the case of perishable goods.

T

The conversion process can be defined as

Main Stock Points in a Production-Distribution System

Adapted from Buffs, ES Modern Production/Operations Management, 7/e. Wiley Eastern Ltd.

Just-in-Time (JIT) is a Japanese innovation, and key features of this were perfected by Toyota

JIT production means producing and buying in very small quantities just in time for use. It is simple hand to mouth mode of industrial operations that directly cuts inventories and also reduces the need for storage space, racks, conveyors, forklifts, computer terminals for inventory control and of course material control personnel. Products are assembled just before they are sold, subassemblies are made just before the products are assembled, and components are fabricated just before the subassemblies are made - so work-in-process (WIP) inventory is low and production lead times are short. To operate with these low inventories, the companies must be excellent in other areas. They must have consistently high quality throughout the organizations.

The JIT transformation begins with inventory removal. Fewer materials are bought, and parts and products are made in smaller numbers; that is the lot size inventories thereby decrease. This immediately results in work stoppages. Production comes to standstill because feeder processes breakdown or produce too many detectives and d-there are no buffer stock to keep things going on. Once this happens, analysts and engineers try to solve the problems and keep things going on. Each round of problem exposure and solution increases productivity and quality too.

Just-in-time (JIT) is a philosophy of improvement through aggressively discovering and resolving any problems or weaknesses that impede the organization's effectiveness and efficiency.

CHARACTERISTICS OF JUST-IN-TIME SYSTEMS

Just-in-time systems focus on reducing inefficiency and unproductive time in the production process to improve continuously the process and the quality of the produce or service. Employee involvement and inventory reduction are essential to JIT operations. Just-in-time systems are known by many different names, including zero inventory synchronous manufacturing , lean production, stock less production (Hewlett- Packard), material as needed (Harley - Davidson ), and continuous flow manufacturing (IBM). In this section we discuss the following characteristics of JIT systems :

People involvement, Team Work, Discipline, Total quality management, pull method of material flow, small lot sizes, short setup times, uniform workstation loads, standardized components and work methods, close supplier ties, flexible work force, product focus, automated production, and preventive maintenance.

People Involvement

Probability all management efforts have some behavioural aspects, because management is working through other people to accomplish the organization's objectives. Management plans and decisions only lay the groundwork. This is the resulting human behaviour that determines a company's success or failure. Such terms as zero inventory and stock less production have given some people the impression that JIT is only an inventory program. JIT has a strong human resources management components that must be recognized if the technical component is to be fully successful. Much of the success of JIT can be traced to the fact that companies that use it train their employees to have the appropriate skill, give them responsibility, and coordinate and motivate them.

The JIT philosophy of continuous improvement and minimization of waste considers waste to be any activity that does not add value to the product or serve the customer in some way. One form of waste that is inconspicuous and difficult to combat is the underutilization of human talent. JIT seeks to utilize more fully the creative talents of employees, suppliers, subcontractors, and others who may contribute to the company's improvement.

Businesses ultimately succeed or fail because of their people. JIT is no exception to this rule. Because JIT is a system of enforced problem solving, having a dedicated work force committed to working together to solve production problem, is essential. JIT manufacturing, therefore, has a strong element of training and involvement of workers in all phases of manufacturing.

Teamwork

First, and foremost, a culture of mutual trust and teamwork must be developed in an organization. Managers and workers must see each other as co-workers committed to the company's success.

Successful people involvement steams from a culture of open trust and teamwork in which people interact to recognize, define, and solve problems. Sometimes it is mistakenly assumed that this component is just another program, such as a suggestion program or a quality circle program. People involvement can include these programs and others, such as adhoc project teams that focus on specific improvement targets and semi-autonomous work teams whose membership seldom changes. The involvement components of JIT is much broader than a program or two: it is a management style and a permanent company wide attitude of teamwork. So that each person works to improve the company. People are encouraged to suggest ways to improve methods which are quickly and fairly considered,

Another important factor that is crucial to JIT is the empowerment of workers. This means that workers are given the authority to take the initiative in solving production problems. Rather than waiting for guidance from above, workers have the authority to stop production at any time for such things as quality problems machine malfunctions or safety concerns.

Discipline

This open, improvement - driven atmosphere does not mean, however, that any employee is free to work by any method he or she choose to try. Usually there is a standard way each job is to be done. If an improvement is suggested and approved, a new standard procedure will be adopted. This standardization prevents variations in products or services which can cause defects. Defects occur- because some variation has been introduced into a material or procedure that normally products good result.

Total Quality Management (TQM)

JIT systems seek to eliminate scrap and rework in order to achieve a uniform flow of materials. Efficient JIT operations require conformance to product or service specifications. JIT systems control quality at the source, with workers acting as their own quality inspectors.

JIT manufacturing depends on a system of TQM being in place. Successful JIT manufacturing goes hand-in-hand with an organization-wide TQM culture.

Pull Method of Material Flow

Just-in-time systems utilize the pull method of material flow. However, another popular method of material flow is the push method.

Small Lot Sizes

Rather than building up a cushion of inventory, users of JIT systems maintain inventory with lot sizes that are as small as possible. Small lot size have three benefits. First, small lot sizes reduce cycle inventory, the inventory in excess of the safety stock carried between orders. The average cycle inventory equals one-half the lot size: As the lot size gets smaller, so does cycle inventory. Reducing cycle inventory reduces the time and space involved in manufacturing and holding inventory,

Second, small lot size help cut lead times. A decline in lead time in turn cuts pipeline (WIP) inventory because the total processing time at each workstation is greater for large lots than for small lots. Also, a large lot often has to wait longer to be processed at the next workstation while that workstation finishes working on another large lot. In addition, if any defective items are discovered, large lots cause longer delays because the entire lot must be inspected to find all the items that need rework.

Finally, small lots help achieve a uniform operating system workload. Large lots consume large chunks of processing time on one workstation and therefore complicate scheduling.

Short Setup Times

Reduced lot sizes have the disadvantage of increased setup frequency. In operations where the setup times are normally low, small lots are feasible. However, in fabrication operations with sizable setup times, increasing the frequency of setups may result in wasting employee and equipment time. Theses operations must reduce setup times to realize the benefits of small-lot production.

Uniform Workstation Loads

The JIT systems work. best if the daily load on individual workstation is relatively uniform. Uniform loads can be achieved by assembling the same type and number of units each day, thus creating a uniform daily demand at all workstations. Capacity planning, which recognizes capacity constraints at critical workstations, and line balancing are used to develop the monthly master production schedule.

Standardized Components and Work Methods

The standardization of components, called part commonality or modularity, increases repeatability. For example, a firm producing 10 products from 1000 different components could redesign its products so that they consist of only 100 different components with large daily requirements. Because the requirements per components increase, so does repeatability; that is, each worker performs a standardized task or work method more often each day. Productivity tends to increase because workers learn to do the task more efficiently. Standardization of components and work methods aids in achieving the high-productivity, low-inventory objectives of JIT systems.

Close Supplier Ties

The JIT philosophy may extend beyond the walls of the company applying JIT, to include, its suppliers. It has an impact on the entire logistics system, or "supply chain." Because JIT systems operate with very low levels of inventory, close relationships with supplier are necessary. Stock shipments must be frequent, have short lead times, arrive on schedule, and be of high quality. . The JIT company can also benefit from the supplier's expertise by having supplier representatives participate in the design phase of few products and recommend improvements. They also work with their suppliers vendors, trying to achieve JIT inventory flows throughout the entire supplier chain.

It can be beneficial to a supplier to work in such a relationship, particularly with a high volume manufacturer. When a company reduces the number of suppliers for an item, the volume of purchase from the remaining supplier or supplier can increase dramatically.

Continuous improvement is central to the philosophy of JIT and is a key reason for its success.

Flexible Work Force

Workers in flexible work forces can perform more than one job. When the skill levels required to perform most tasks are low, a high degree of flexibility in the work force can be achieved with little training. In situations requiring higher skill levels, such as at the Hi-tech industries, shifting workers to other jobs may require extensive, costly training. Flexibility can be very beneficial. Workers can be shifted among workstations to help relieve bottlenecks as they arise without resorting to inventory buffers. This is an important aspect to the uniform flow of JIT systems. They can also step in and do the job for those on vacation or out sick. Although assigning workers to tasks they don't usually perform may reduce efficiency, some rotation relieves boredom and refreshes workers.

Product Focus

A product focus can reduce the frequency of setups. If volumes of specific products are large enough, groups of machines and workers can be organized into a product layout to eliminate setups entirely. It volume is insufficient to keep a line of similar products busy, group technology can be used to design small production lines that manufacture, volume, in families of components with common attributes. Changeovers from a component in one product family to the next component in the same family are minimal.

Automated Production

Automation plays a big role in JIT systems and is a key to low-cost production. Sakichi Toyota, the founder of Toyota, once said "whenever there is money, invest it into machinery". Money freed up because of JIT inventory reductions can be invested in automation to reduce costs. The benefits, of course, are greater profits, greater market share (because prices can be cut), or both. Automation should be planned carefully, however, many managers believe that if some automation is good, more is better. That isn't always the case.

Preventive Maintenance

Because JIT emphasizes finely tuned material flows and little buffer inventory between workstations, unplanned machine downtime can be disruptive. Preventive maintenance can reduce the frequency and duration of machine downtime. After the technician has performed routine maintenance activities, he/she can rest other parts that might need to be replaced. Replacement during regularly scheduled maintenance periods is easier and quicker than dealing with machine failures during production.

Maintenance is done on a schedule that balances the cost of the preventive maintenance program against the risks and costs of machine failure.

Another tactic is to make workers responsible for routinely maintaining their own equipment and develop employee pride in keeping their machines in top condition.

Production Methods

Processes are designed so that there is less specialization of workers. The physical layout is arranged so that a worker can operate two or three different machines, thus providing flexibility in processes that might precedes the assembly line. The benefits that result from this organisation of multi-function workers are:

• reduction of inventory between what would otherwise be separate processes
• decrease in the number of workers required, resulting in a direct increase in productivity
• increased worker satisfaction because of more broadly defined jobs
• multi-functional workers can engage in teamwork

There are three elements of job standardization that are included on a standard operation sheet stacked up for all workers to see:

Cycle time, operations routing, and standard quantity of work in process.

Based on the computed cycle time that is derived from market demand, the aggregate number of workers required to produce one unit of output in the cycle time is determined. Rebalancing may then be necessary to schedule for minimum labour input for a given output objective. The standard quantity of work input for a given output objective. The standard quantity of work in process indicates the in-process inventory required for smooth flow.

The smoothing of production is regarded as the most critical element in the

Just-in-Time objective.

 As will be described in more detail under the heading Kanban which follows, workers go to the preceding process to withdraw the required parts and components for their operations. If there are fluctuations in the rates at which these materials are withdrawn, then the preceding process must hold buffer in-process inventories to give off the-shelf service. The required in-process inventories would increase also for upstream processes. This results in the objective of minimizing production fluctuations in the final assembly line by scheduling small lots of individual models, and focusing "all out" efforts on minimizing.

JIT does not come free-certain changes to the factory and the way it is managed must occur before the benefits can be realized. Among these changes are:

1. Stabilize production schedules.
2. Make the factories more focused.
3. Increase production capacities of manufacturing work centers.
4. Improve products quality.
5. Cross-train workers so that they are multi skilled and competent in several jobs.
6. Reduce equipment breakdowns through preventive maintenance.

PREREQUISITES FOR EFFECTIVE JIT

Following are the prerequisites for effectively implementing Just-in-Time strategy in a manufacturing system :

(a) Low variety of items being processed.

(b) Demand Stability

(c) Vendor reliability (to ensure reliable supply) of Production Management

(d) Defect free materials (to avoid disruptions).

(e) Good communications (to help ensure continuous operation and minimum disruption.

(f) Preventive maintenance (to avoid disruption).

(g) Total Quality control.

(h) Management Commitment.

 (i) Employee Involvement.

 (j) Worker Flexibility.

THE KANBAN SYSTEM-

Suppose a manufacturer gives a production schedule to the work center. This is the work center that sends the finished parts to the finished goods area. Imagine that the supervisor of the work center has to build fifty units of product on the same day. Then the supervisor checks the parts or raw materials available at hand and if he doesn’t have the required number of them he will send a request to the previous work center that supplies the part asking for the quantity required for building the product. In this way system use to pull parts as well as subassemblies towards the work center. In the Kanban system, a work center requests materials from other using a card called a Kanban.

The push system is a unidirectional process whereas the pull system is a double flow process. In a push system the build schedules and materials flow in the same direction whereas in pull system materials travel in one direction while the build schedule travel in opposite direction.

Subsequent and Preceding Processes

 A subsequent process is defined as that manufacturing process, which is carried out after the current process. On the contrary, which is done before the current process will be its preceding process. For example, a work center that receives assembled parts is a subsequent process to the process that assembles the parts and the same is the preceding process for the work center. A Kanban will always send parts to subsequent processes and it will always obtain the parts from the preceding process. In brief, a Kanban system comprises a set of cards that travel between preceding and subsequent processes, communicating what parts are required in the subsequent processes.

Types of Kanban

A Kanban system requires two types of Kanbans for its successful operation :

 (a) A withdrawal Kanban

(b) A production Kanban

 Withdrawal Kanbans

These travel between the work centers and are used for authorizing the transfer of parts from one work center to another. In a Kanban system, they always accompany the flow of material from one process to another. A withdrawal Kanban must indicate the part number, revision level, lot size and the routing process. Withdrawal Kanbans must show the preceding process as well as subsequent process’s names and their locations.

Production Kanbans

The job of the production Kanbans is to release an order to the preceding process for building more parts. The interaction between production and withdrawal Kanbans at three work centers can be explained through the following way. There is a staging area where the production Kanbans waits for the withdrawal Kanbans to arrive to fetch parts. Also note the withdrawal Kanbans supply the parts into the work center’s process exactly where they belong. On the contrary, as the work center utilizes parts to build its products, its production Kanban will generate withdrawal Kanbans at the work center’s preceding process.

Kanban : Rules and Philosophy

Seven rules control the operational environment of Kanban system. These rules are simple but any violation of them will cause disturbance in the system, resulting in wastage of materials and labour. The Kanban rules are in agreement with Just-in-Time system principles. These rule are aimed at avoiding excess inventory on the manufacturing floor. These are :

Rule 1 : Move the Kanban Only When the Lot it Represents is Consumed

 This rule calls for the subsequent process to withdraw the necessary parts from the preceding process in the necessary quantities and at exact time needed. A subsequent process must send a Kanban to the preceding process asking for more parts only after the subsequent process has consumed all the parts that the Kanban was escorting.

Rule 2 : No Part Withdrawl Without a Kanban is Allowed

The movement of parts from a preceding process to a subsequent process is Just-In-Time allowed only by the use of a Kanban. No preceding process can move parts without the authorization of a Kanban request.

Rule 3 : The Number of Parts Issued to the Subsequent Process must be the Exact Number Specified by the Kanban

 The preceding process must not issue Kanbans with a partial count of parts. They must have the exact quantity specified by the Kanbans. On the other hand, if only a partial number of parts are available in the preceding process, a line shortage is created. The Kanban must wait until the preceding process produces enough parts to meet the number requested by it.

Rule 4 : A Kanban Should Always be Attached to the Physical Products

A Kanban is a traveling card, and it will always travel alone from the subsequent process to the preceding process to request new parts. But once the worker attaches the Kanbans to a new lot of parts, the card must travel with the lot until the last part is used. The Kanban should be attached to the lot in such a way that it is always visible to the workers.

Rule 5 : The Preceding Process Should Always Produce its Parts in the Quantities Withdrawn by the Subsequent Process

This is a rule which says that processes should never overproduce parts in any quantity, for this is a waste of labour and materials.

Rule 6 : Defective Parts Should Never be Conveyed to the Subsequent Process

This rule concerns the quality of the parts moved by the Kanban. In a Just-In-Time system, there is an absolute need to maintain high quality in the production of parts and subassemblies as there are no buffer inventories to cover for defective parts.

Rule 7 : Process the Kanbans in Each Work Center Strictly in the Order in which They Arrive

 When a work center has in its mailbox several Kanbans from different processes, the operators in that work center must serve the Kanbans in the order in which they arrived.

Kanban Production Control Systems

 A Kanban control system uses a signaling mechanism to control JIT flows. In a paperless control system, containers may be used as a substitute of cards. The cards or containers made up the Kanban pull system. The authority to manufacture or provide additional parts comes from downstream operations.

When the assembly line takes the first part A from a full container, a worker takes the withdrawal Kanban from the container, and takes the card to the machine center storage area. In the machine center area, the worker finds a container of part A, removes the production Kanban, and replaces it with a withdrawal Kanban. Placement of this card on the container authorizes the movement of the container to the assembly line. The freed production Kanban is placed on a rack by the machine center, which authorizes the production of another lot of material. Control & Measurement of Production Management Cards are not the only way to signal the need for production of a part; some other possible approaches are :

 Container System

 In this case an empty container on the factory floor visually signals the need to fill it. The amount of inventory is adjusted simply by adding or removing the containers.

 Kanban Squares

 Certain companies use spaces on the floor or on the table to identify where the material should be stored. When the square is empty, like the one on the left, the supplying operations are authorized to produce; when the square is full, no parts are needed.

 Coloured Golf Balls

When a part used in a subassembly is down to its queue limit, the assembler rolls a coloured golf ball down a pipe to the replenishment center. This tells the operator which part to make next.

Determining the Number of Kanbans Needed

 The process of setting a Kanban Control system requires determining the number of Kanban cards needed. In a two-card system, the number of sets of production and withdrawal cards is required to be determined. Accurately estimating the lead time needed to produce a container of parts is the key to determine the number of containers. This lead time is a function of the processing time for the container, any waiting time during the production process, and the time required to transport the material to the user. Enough kanbans are needed to cover the expected demand during this lead time plus some additional amount for safety stock. The number of Kanban card sets is

K = Expected demand during lead time + Safety stock

       Size of the container

 k = DL S (1 ) C + = where, k = Number of kanban card sets,

 D = Average number of units demanded over some time period,

 L = Lead time to replenish an order (expressed in the same units as demand),

S = Safety stock expressed as a percentage of demand during the lead time, and

 C = Container size.

JIT Applications for Line Flows

 The figure illustrates a pull system in a simple line flow. In a pure JIT environment, no employee does any work until the product has been pulled from the end of the line by the market. The product could be a final product or a component used in later production. When a product is pulled, a replenishment unit is pulled from upstream operations. In Figure, an item of finished goods is pulled from F, the finished goods inventory. The inventory clerk then goes to processing station E and takes replacement product to fill the void. This pattern continues up the line worker A, who pulls material from the raw material inventory. The rules of the flow layout require employees to keep completed units at their workstation, and if someone takes the completed work away, the employee must move upstream in the flow to get additional work to complete.

JIT Application in Job Shops

JIT is traditionally applied to line flows, but job shop environments also offer JIT benefits. The focus of JIT is product flow. Although job shops are characterized by low volume and high variety, JIT can be used if demand can be stabilized to permit repetitive manufacture. Stabilizing demand is usually easier to accomplish when the demand is from a downstream production stage rather than an end customer.  Factory machining centers, paints shops, and shirt making are example of job-shop type operations that process parts and components before they reach final production stages.

JIT IMPLEMENTATION IN MANUFACTURING AND SERVICE FIRMS

Many JIT techniques have been successfully applied by service firms. Just as in manufacturing, the suitability of each technique and the corresponding work steps depends on the characteristics of the firm’s markets, production and equipment technology, skill sets and corporate culture. Service firms are not different in this respect. Some successful applications are mentioned below.

Organise Problem Solving Groups

 Just-In-Time Bluewell is extending its quality circles from manufacturing into its service operations. Other corporations as diverse as Standard Company, Killer Brewing Company are using similar approaches to improve service. Many airways used quality circles as a fundamental part of its strategy to implement new service practices.

Upgrade House Keeping

Good house keeping means more than winning the clean broom award. It means that only the necessary items are kept in a work area, that there is a place for everything, and that everything is clean and in a constant state of readiness. The employees clean their own areas.

Many service organizations such as McDonald, Disneyland have recognized the critical nature of house keeping. Their dedication has meant that service processes work better, the attitude of continuous improvement is easier to develop, and customers perceive that they are receiving better service. Upgrade Quality

The only cost-effective way to improve quality is to develop reliable process capabilities. Process quality is quantity at the source which it guarantees first time production of consistent and uniform products and services.

 Clarify Process Flows

 Clarification of flows based on JIT themes can dramatically improve the process performance. Here are few examples. First, Federal Express Corporation changed air flight patterns from origin to destination to origin to hub, where the freight is transferred to an outbound plane heading for the destination. This revolutionized the air transport industry. Second, the order-entry department of a manufacturing firm converted from functional sub-departments to customer-centered work groups and reduced the order processing lead time from eight to two days. Third, a country government used the JIT approach to cut the time to record a deed transfer by 50%. Finally, supermaids sent in a team to house cleaners, each with a specific responsibility to clean each house quickly with parallel processes. Change in process flows can literally revolutionize service industries.

 Eliminate Unnecessary Activities

A step that does not add value is a candidate for elimination. A step that does add value may be a candidate for reengineering to improve the process consistency or to reduce the time to perform the tasks. A hospital discovered that significant time was spent during an operation for an instrument that was not available when the operation began. It developed a checklist of instruments required for each category of operation. Speed Lube eliminated steps, but it also added steps that did not improve the lubrication process but did not make customers feel more assured about the work being performed. Introduce Demand Pull Scheduling

Due to the nature of service production and consumption, demand-pull scheduling is necessary for operating a service business. Moreover, many service firms are separating their operations into “black room” and “customer contact” facilities. This approach creates new problems in coordinating schedules between the facilities.

Develop Supplier Networks

 The term supplier networks in the JIT context refers to the cooperative association of suppliers and customer working over the long term for mutual benefit. Service firms have not emphasized supplier network for materials because the service organizations like McDonald’s, one of the biggest food products purchasers in the world. A small manufacturer recognized that it needed cooperative relationships for temporary employees as well as for parts. It is considering a campaign to establish JIT-type relationships with a temporary employment service and a trade school to develop a reliable source of trained assemblers.

ADVANTAGES AND DISADVANTAGES OF THE JUST-IN-TIME PHILOSOPHY

Various advantages and disadvantages of the just-in-time philosophy and Kanban are listed in tabular form in Table

: Advantages and Disadvantages of JIT and Kanban

                                                                                  

Feature	Advantages	Disadvantages
Small workin-process inventories	Decreases inventory cost. Improves production efficiency. Points out quality problems quickly.	May result in increased worker idle time. May decrease the production rate
Kanban information flow system	Provides for efficient lot tracking. Inexpensive means implementing just-in-time. Allows for predetermined level of WIP inventory by presenting number of Kanban tickets.	Slow to react to changes in demand. Ignore known information about future demand patterns.
Coordinated inventory and purchasing	Inventory reduction. Improves coordination of different systems. Improves relationships with vendors.	Decreases opportunity for multiple sourcing. Suppliers must react more quickly. Improves reliability required of suppliers

Jidoka : An authority given to workers to stop the assembly line when quality problems are encountered.

Poka-Yoke : Any tool proof device or mechanism that prevents defects from occurring.

Kaizen : A Japanese term which is used for a system of continuous improvement.

5S Kaizen The 5S steps of housekeeping, with the Japanese names and their meanings are as follows :

 (a) SEIRI : Sort - Clear Out

(b) SEITON : Straighten – Configure

 (c) SEISO : Scrub - Clean and Check

(d) SEIKETSU : Systematize - Conform and Continue

 (e) SHITSUKE : Standardize - Custom and Practice

SEIRI (Sort-Clear Out)

 Under this principle first we classify all items into in two categories in terms of necessary and unnecessary. And then the latter is discarded or removed. Usually, a ceiling on the number of necessary items should be established otherwise everything may look like necessary in one way or the other. In usual situations, the department is found with full of unused machines, jigs, dies and tools, rejects, work in process, used/unused materials, supplies and spare parts, sleeves, containers, desks, work benches, files of documents, carts, racks, pallets and many more other materials. A rule of thumb can be taken as to remove anything that will not be used within next 30 days.

How to do?

 (a) SEIRI begins with a red tag campaign.

 (b) Select an area for SEIEI,

(c) Designate appropriate 5-S team and delegate suitable authority.

 (d) Team members go to the site with a handful of red tags and place them on the item they believe are unnecessary.

(e) If red tags are found on items actually required by the site managers, they must demonstrate the necessity for such items.

(f) The specific material that is not required in the next thirty days but may be needed in the near future, are moved to their appropriate places such as the warehouses.

SEITON (Straighten-Configure)

SEITON means configuring the items marked as ‘useful’ and arranging them so as to minimise search time and effort. The minimum number of needed item can be of no use, if they are stored too far from the work station or in a place where they can not be found. How to do?

 (a) Each item must have a designated address, name and volume.

 (b) Floor space for bins containing WIP or supplies must be marked by painting.

(c) Maximum allowable number is indicated clearly.

 (d) In nut shell, each item should have its own address and conversely each space should have its designated address.

(e) Each wall can be numbered.

 (f) The gang ways should be marked clearly.

SEISO (Scrub-Clean and Check)

SEISO is cleaning and also checking. Clean the working environment, including machines and tools, floors, walls and other areas of the shop floor, because when the machine is covered with oil, soot and dirt, it is difficult to identify any problem that may be developing. It is understood that most machines go under breakdown due to vibration, or wear debris or introduction of foreign particles or due to inadequate lubrication. SEISO is a great learning experience for the operators of the machine, since they can make many useful innovations regarding the cleaning of the machines. Naked electrical wires may be covered safely while cleaning the machine.

 SEIKETSU (Systematize – Conform and Continue)

SEIKETSU is interpreted in two ways. One is that to keep each individual safe, clean, neat and tidy by wearing proper and safe working dresses, using safety glasses, gloves and shoes as well as maintaining a clean, healthy working environment. Another interpretation is to adhere to work on SEIRI, SEIRON and SEISO continually and everyday, i.e. systematically observe the above three as a part of the job in the system. For instance, it is easy to go through the process of SEIRI once a while and make some improvements, but without an effort to continue such activities, the situation will soon be back to where it was started.

 SHITSUKE (Standardize - Custom and Practice)

Plant managers must determine who should be involved and the frequency, i.e. how often the 5S team should visit the entire factory. These should take place in such a way that the 5S programme should not disturb the regular work and should not cost in terms of money and time. Thus, a standard procedure, duration, frequency, responsible and authorized persons, etc. for this purpose are to be made. The people concerned should be trained properly about the 5S system and about the significance of housekeeping, cleanliness, orderliness and traceability of the items.