Just-in-time Production Philosophy

Introduction

Leading companies around the world have adopted this new management philosophy, giving rise to extraordinary advances in terms of quality, agility in deliveries, and costs.

Competitive advantage

We can enumerate five variables that will serve as the basis for achieving this competitive advantage: cost, quality, service, flexibility, and innovation. This set of decisions constitutes what is called production strategy.

The just-in-time (JIT) philosophy

The JIT method is not just another project to eliminate waste or waste.

The Just-in-Time system has four essential objectives, which are:

• Attack the fundamental problems.
• Eliminate waste.
• Search for simplicity.
• Design systems to identify problems.

Attack the fundamental problems.

Establish systems to identify problems.

With JIT, any system that identifies problems is considered beneficial and any Established mechanisms to identify problems.

1. Being willing to accept a short-term reduction in efficiency in order to gain a long-term advantage.

The objectives of Just-in-Time are usually summarized in the so-called “Theory of Five Zeros”, these being:

• Zero time to market.
• Zero defects in products.
• Zero waste of time.
• Zero working paper.
• Cero stock.

To which a sixth “Zero” is usually added:

• Zero accidents.

Cost/benefit of the Just-in-Time application

With the application of JIT, all the expenses involved are mainly training expenses.

Just-in-Time is synonymous with simplicity, efficiency, and a minimum of waste.

Complete analysis of non-productive costs

Current capacity = work + loss

The preliminary step for the application of the just-in-time production system is to fully identify non-productive costs such as:

• Unproductive costs due to excess production.
• Unproductive costs in the time of workers (unemployed).
• Unproductive costs for transportation.
• Unproductive costs of the processing itself.
• Unproductive costs of available stock (inventories).
• Unproductive costs for other activities.
• Unproductive costs in the manufacture of defective products.

By eliminating these unproductive costs completely we can improve operating performance by a wide margin. The just-in-time production system clearly reveals excess labor. The definition of waste that Western companies have assumed is “anything other than the absolute minimum resources of material, machines and labor required to add value to the product”. Considering as absolute minimum resources:

• A single provider, if it has sufficient capacity.
• No people, equipment, or space is dedicated to repeating a job already done.
• No safety stock.
• No excessive lead time.
• Let no one carry out a task that does not add value.

“Only those activities that physically change the products add value.” In other words, counting, moving, or even inspecting are tasks that do not add value, but do add cost; therefore they are wasteful.

Operational advantages provided by a strong reduction in stock and deadlines

Increased agility, and better market monitoring.

• Ability to meet urgent orders.
• Speed ​​of reaction thanks to the reduction of deadlines.
• The best response to market expectations.
• Possibility of planning short-term production taking into account only firm orders (instead of planning based on forecasts).

Improved productivity and reduced production costs.

• Reduction of expensive and rigid finished product warehouses.
• Suspension of tasks related to the management, handling, transport, surveillance, and protection of warehouses (risks of fire, theft, corrosion, etc.).

space gain

• Low rent or possibility of using the area gained for other activities.
• Possibility of optimizing the implementation of activities.
• Suppression of the need to occupy other buildings later due to the extension of the activity.

Efficiency improvement

• Greater visibility.
• Decrease in the number of information to take into account.
• Better circulation of information.
• Reduced number of missing parts.
• Waste reduction.

Reduction of investment needs and relative maintenance charges:

• To the extent of the premises.
• Warehouse handling equipment: forklifts, containers, pallets, and overhead cranes, among others.
• To store equipment (traditional or automatic).
• To the warehouse management computer system.

Reduction of routes

Complexity is not inevitable, making it possible to considerably improve the distribution of activities in factories. The disposition in cells of the workshops.

• Geographical separation and online manufacturing of different products.
• Other activities to be located close to each other.
• The decentralization of reception, storage, and dispatch activities.

Machine cells

One cell corresponds to the minimum route that a part treated by each of its machines would have to carry out. It allows chaining the successive operations related to the same part, thus minimizing the terms. Parts are easily located.

Activity groupings

Not all factories can be “targeted” by-products and brought online. It is convenient immediately to chain their operations and eliminate intermediate warehouses.

Quick tool change

In factories, the machines are most often multipurpose, which allows them to obtain a high utilization rate, guarantees their profitability, and reduced production costs. To go from one type of production to another you have to change “the tool” of the machine.

The idea of ​​reducing tool change times is therefore not traditional in the industry. A sharp reduction in tool change times would, however, offer multiple advantages. A few very simple ideas are enough: changing all clamping systems to instant locking systems, reducing the number of screws and bolts, creating tool kits tools permanently located next to the machine, installation of a stock of tools next to the machine, tools transported by a truck dedicated to the machine, review of the sequence of operations, creation of setting gauges, among many other changes. A program of generalized reduction of the times of change of tools is an imperative of competitiveness for all industrial companies.

SMED application. It is made up of four stages:

1. Know the real conditions of the preparation to improve. We proceed to analyze and identify the preparation times with the use of a stopwatch.
2. Separate internal preparation from external preparation. It is a question of separating the tasks according to their nature into internal or external ones and carrying out the external ones while the machine is working. In this way, reductions of between 30 to 50 percent of the time spent on internal preparation can be obtained.
3. Convert internal preparation to external. This stage is divided into two phases: in the first phase it is about re-evaluating the procedures declared as internal and, without making changes to the processes, see if there is the possibility of doing any with the machine running, that is, converting it into external. In the second phase, which is carried out jointly with the first, working with the processes that are intrinsically internal, the way to convert them into external ones is sought, making the necessary modifications.
4. Refinement of all aspects of preparation. Although with the three previous stages, it is possible to have reached less than ten minutes, this does not mean we have to stop and be satisfied with what we have achieved but, as the Japanese are used to, we will continue reducing the preparation time, both internally and externally.

Usual enhancements for quick tool change

1. Avoid displacements, waiting, wasting time, searching, and the need to choose. Have everything you need next to the machine. This is achieved by: tool kits, gauge gauges, and adjustment instruments, next to the machine; materializing areas for classified placement of supplies in lockers.
2. Dedicate means of maintenance. Eliminate physical efforts. This is obtained thanks to tool carts at the height of the machine; devices for positioning the tool (bearings, slides); pneumatic or hydraulic jacks for lifting tools; and revision of the design of the tool so as not to have to disassemble more than a reduced part of the tool.
3. Reduce tool clamping times. Reduce the number of bolts and screws; reduce the length of bolts and screws; replace the holes with notches and notches (in order to avoid having to completely unscrew the bolts
4. Reduce adjustment and connection times. By normalizing tool heights, shims, color signals, graduations, notches; adjustment templates; presence, next to the machine, of a test sample of the type to be produced.
5. Perform tasks outside of hours. Cleaning, maintenance, and sharpening of tools; cleaning, control, and contrast of gauges; tool preheating; and partial disassembly of the previous tool.
6. Check conception. Standardization of the pieces to produce; and standardization of the dimensions of tools and molds.

The removal of random risks

Numerous random risks can disrupt the production and operation of traditional factories, such as missing parts, shipping delays from suppliers, frequent machine breakdowns, and quality defects in manufactured products. Safety margins here take the form of high stocks and long terms, which are accompanied by disorder, productiveness, and sharp increases in costs.

The reliability of the machines

This lack of availability seriously cuts the production capacity of the machines and, with it, increases the average cost of production. The lack of availability of equipment is the result of two phenomena: lack of reliability and insufficient maintenance. The lack of reliability explains the high frequency of breakdowns and incidents. Defective maintenance translates into long repair and tune-up times.

Breakdowns and incidents in the operation of machines can present multiple aspects. An industrial machine is a complicated system, composed of mechanical, hydraulic, electrical, and electronic elements. The possibilities of breakdowns or incidents are therefore multiple.

It should be noted that these machine inadequacies rarely require replacement with newer equipment. The design of the machines can also be responsible for some repairs because the elements are difficult to access, not very modular, or require too much time to replace.

Production being the raison d’être of the factories, the machines are used to the greatest possible degree. It is therefore difficult to find time for maintenance. This lack of cleanliness produces disastrous effects on the reliability of the machines. The layer of dirt that covers a machine prevents an oil leak from being seen, which presages a further breakdown.

The correct thing is to implement preventive and predictive maintenance. Preventive maintenance consists of systematically carrying out interventions, essentially to change elements and put the machines back in good condition.

The set of such actions can be grouped under the term “Total Productive Maintenance”, of which preventive and predictive maintenance only represent two aspects.

The actions to be carried out are inspired by three simple ideas:

1. To reduce the number of failures in a machine, it is necessary, above all, to know what happens to it.
2. To improve the use and monitoring of the machine, it is necessary to involve its operator.
3. Given the many instances of machine breakdowns or incidents, it may seem difficult to rapidly reduce their frequency. In fact, it is enough to be logical: you have to start by fighting against the main problems.

Thus improving the safety of men and machines (Zero Accidents). Focus primarily on the most frequent problems. After a single week of putting into practice the notebooks or monitoring software, it is easy to identify the two or three types of breakdowns or incidents that most frequently immobilize the machine. In this way, we proceed to attack those breakdowns that generate major problems in the regular operation of machines and equipment. It will then be necessary to proceed with the improvement of the machine. Incident due to misuse of the machine. Incident due to lack of regular maintenance or cleaning. The operator must be in charge of cleaning and regular maintenance of the machine or equipment. Incident due to normal wear, caused by the operation of the machine.

The problem of reliability cannot be reduced to the treatment of serious breakdowns through preventive maintenance.

Cleaning of each machine by its operator.

• Machine improvements.
• Improvements in the conditions of use.
• Operator training.
• Conservation is carried out by the operators.
• Preventive Maintenance.
• Predictive Maintenance.
• Maintenance from the conception of the machine or equipment, by improving its reliability and ease of maintenance.

For this purpose, a scheme of Total Productive Maintenance (TPM) is given below.

Total Productive Maintenance

Something vital both to improve quality, as well as to reduce inventories and reduce idle times for both machines and personnel, is to establish the Short Setup Time (SMED) and Total Productive Maintenance systems.

Total productive maintenance is an approach to equipment maintenance that results in zero downtime.

Production quality

Producing a defective part that must be discarded in the middle of the production process represents, on the one hand, the loss of the investment made in the part until the defect has arisen, but also causes us to manufacture another part to replace it and be able to continue with the process. productive, so the total cost of the defective part is, on the one hand, the part itself plus the costs of replacing it.

The four levels of quality management

Different levels can be detected in the different companies in which the quality management system can be framed, depending both on the development of the existing quality system and on what is the focus of attention in each one of them.

Level 1: Inspection. At this level, it is assumed that the company produces quality defects and there is a team or department dedicated solely and exclusively to separating the products. However highly evolved the inspection may be, if this is the only tool used to achieve quality products, we will be at the low level of quality systems. In the most evolved quality systems, there is also inspection, but the philosophy is totally different. It is not about inspecting to eliminate defective products but comparing the quality obtained with the planned quality, studying the deviations, and correcting the process to obtain the desired quality. The most ambitious quality systems like Six Sigma don’t even accept the possibility of defective products. In these systems, the final inspection can be eliminated by replacing it with process inspections. If the process is controlled, the final quality will be as planned.

Level 2: Quality Control. The application of statistical techniques to production processes allows us to obtain very valuable information on production processes. We can determine the capacity of a process, that is, demonstrate if the process is sufficiently well prepared to produce without quality defects under normal conditions.

Level 3: Quality Assurance. Quality assurance is one more step in the evolution of quality systems because in these systems all company departments are involved, not only the quality department, greater importance is given to the human factor in the company, and management of the company begins to take the leadership role in the achievement of quality objectives. However, quality assurance systems are not the most evolved quality systems known because they have a specific quality objective and are limited to ensuring that level of quality without worrying about exceeding it. Although the best-known quality assurance systems such as ISO 9000 and others encourage continuous improvement, these systems are not sufficiently evolved to achieve permanent improvements in processes.

Level 4: Total Quality. Total quality integrates all the quality elements of the previous levels but extends them to all levels of the company and to all its personnel. It is at this level that the companies that have implemented the Just-in-Time System operate.

At present, companies with quality systems of different levels coexist in the competitive arena, despite the increase in competition and the globalization of markets are inexorably pushing companies to develop more evolved quality systems.

The basic pillars of any quality system

The pillars on which any effective quality system must be based are:

• The conviction of the Directorate.
• Training of managers and staff.
• Statistical Process Control.
• And, Continuous Improvement.

Management conviction. The conviction of the Management is fundamental and indispensable for the purpose of building the Total Quality System. Quality systems are based on improvement strategies in the very long term or elements that are difficult to assess in the short term.

Companies with a Just-in-Time system have to choose the most beneficial alternative in the long term

Training. Another of the pillars on which quality systems are based is training. In the words of the Japanese consultant Ishikawa “Quality begins and ends with training. The quality systems look for the use of all the capacities of the employees of the company, not only the already demonstrated capacities but also the potential ones. Two aspects must be highlighted when we refer to the concept of training in quality systems.

Statistical Process Control and Continuous Improvement

The entire quality system must seek a single objective: to manage to organize the company’s activities and create the appropriate management structure to allow continuous improvement.

Relationship with suppliers

The uncertain quality of the products delivered. The quality demands expressed by the company to its suppliers have the character of good wishes without being accompanied by any demand for proof of quality control of the delivered products.

A large number of vendors and antagonistic relationships. For this reason, the company has thousands of names in its supplier file. The company cannot hope to compete with its international competitors if it maintains antagonistic relationships with suppliers that deliver their orders infrequently, with long lead times, and without quality assurance. Currently, it is crucial to destroy the barriers that separate the company from its customers and suppliers.

The participation of suppliers in the design stage of the company’s products and services is of fundamental importance.

The Kanban

Kanban is considered a subsystem of the Just-in-Time system. In the system in question each process

What is a Kanban?

A Kanban is a tool to achieve “Just-in-Time” production. Two main types are used: the transportation Kanban and the production Kanban. The first specifies the type and quantity of product to be withdrawn by the subsequent process, while the production Kanban indicates the type and quantity to be manufactured by the previous process, and for this reason is called process Kanban.

Author’s conclusions

The Just-in-Time system forms a broader system called Kaizen, a system that, pursuing continuous improvement, allows for a systematic and sustainable reduction of both cost and failure levels, while increasing productivity and customer satisfaction levels.

Essay comments

The Just In Time production methodology is aimed at continuous processing, without production interruptions. In the just-in-time application, production times are considerably reduced, since when producing in small batches, defective parts are easily detected in each of the departments that enter the production process, thus keeping a control that allows at any time modification process that causes the deviation.

The work that adds value to production is that which, during the processing of materials and components, represents one more addition to the final product.

just-in-time benefits

• Investments are reduced to maintain inventory. Increase inventory turnover.
• Reduce material losses. Improve overall productivity. Lower financial costs.
• Savings in production costs. Less storage space.
• Quality problems and bottlenecks are avoided. coordination problems, unreliable suppliers, etc.
• Rationalization in production costs. Obtaining little waste. Effective knowledge of deviations.
• Decision-making at the right time.
• Each operation produces only what is necessary to meet demand. There are no random or disorderly processes.
• The components involved in production arrive at the time of being used.

Environment for just-in-time application

The Just in Time methodology as a management procedure and product management can be used in any type of company, both industrial and service.

Thematic attachment

The philosophy that frames just-in-time production is to produce only the necessary quantities of product at the time that customers require.

Just in time vs. traditional production

The main differences between the Just in Time model and the traditional production methodology are summarized below:

Inventories decrease

The Just in Time system seeks to reduce inventories to very low levels, while in the traditional system, materials are supplied and transferred to the next process without taking into account the level of existing demand.

In traditional production, products move from a group of identical machines to another department with machines that perform other specific jobs. Just-in-Time replaces this pattern with one of the production cells in which machines are grouped into families and arranged in such a way that a series of sequential operations can be carried out.