1. Principles of Total Productive Maintainance

Total Productive Maintenance (usually simply called TPM) is a particularly comprehensive and popular programme to promote continuous improvement in all areas of a company.

Especially in the automotive industry, TPM is used to support the success driver for a company already mentioned above: namely, a trouble-free production system without losses or waste with as few defects, downtimes, accidents as well as quality losses as possible.

Where does TPM come from?

Do you remember the preventive maintenance strategy? This approach was popular in America in the mid-20th century under the name “Preventive Maintenance” – so popular that Japanese companies began to adopt and adapt this concept to prevent operational failures.

Over the course of several decades, this led to the development of various maintenance concepts, which were brought together in TPM from the 1970s onwards. Related to this are the concepts of Kaizen and Lean Production, which were also developed in Japan and are based equally on continuous improvement and the avoidance of weak points.

In TPM, eight different “pillars” are defined, each of which is to be built up and further developed in the company. These pillars are:

Continuous improvement

This basic principle of quality management provides for continuous improvement in smaller steps (comparable to the previously mentioned Kaizen), carried out by working groups or teams. The flexibility and interaction of the employees in the company should also be promoted. Important support for action is the so-called PDCA circle:

Figure 3 (created with Smart-Art in Word)

Autonomous maintenance

The staff that operates the system should be largely trained in the functioning and maintenance tasks of the system in question. In this way, they can independently carry out simple maintenance tasks such as inspecting, cleaning, and lubricating, as well as smaller maintenance tasks. Standing and waiting times can thus be greatly reduced.

Planned maintenance

This is a method of the already mentioned predictive maintenance to ensure the highest possible availability and the failure safety of all machines and plants. This is proactively improved through planned downtimes.

Competence management

This pillar is also called “training and education”. The competencies of the employees at the plants in terms of TPM are to be ensured on three levels: professional (i.e., technical knowledge), methodological (the knowledge about the correct implementation of TPM) as well as social (working in a team).

Start-up monitoring

This aspect concerns the phase from the first prototype development to the production capability of the final product. TPM aims to achieve a “start-up curve” that is as vertical as possible, i.e. essentially to be able to meet new market demands as quickly as possible.

Quality management

Using this pillar, one deals with the minimization of quality defects – both in the end product and in the plant itself. Errors that occur in production should be recognized and eliminated. An important keyword here is the so-called “Poka Yoke” – this means the avoidance of unintentional errors through the approach that each tool and each process can only be used correctly in one way.

TPM in administrative areas

This pillar also deals with the implementation of TPM in company departments that are not directly involved in the production, to minimize losses and waste there as well – for example in purchasing, logistics or human resources. A classic example is a tidy office workplace. The 5S method, which we will look at in more detail below, is popular here.

Occupational safety, environmental and health protection

This pillar concerns the sensitization of employees to potential hazards and risks in the work environment. The aim is to reduce accidents affecting the staff or the environment to zero or to minimize the consequences by practising emergencies.

To be able to use TPM in the company, key figures are indispensable. These form the benchmark for all activities. The most important key figure is the so-called total plant effectiveness – essentially the total added value of the plant.

Depending on the company, there are also the following key figures that can be consulted and adapted accordingly: Productivity (e.g., value-added per person), quality (e.g. how often a defect occurs), costs (e.g. maintenance costs), delivery (e.g. quantity of stock), safety (e.g. several accidents) and morale (e.g. a number of suggestions for improvement from employees).

A company manufacturing mainly transmissions (manual and automatic) and engines (petrol and diesel), with 75 employees, started its lean journey when one of its customer’s engineers visited the facility and made a recommendation to implement 5S. The company has also standardized the way components are handled, the bench layout, workplaces, and the tooling that is used. An employee can now move from one workbench to another and recognize everything that is there. Workbenches are dedicated to particular product types. Different baskets for different gearboxes have been designed to standardize transportation boxes. The company keeps all components from each gearbox in a single storage tray. This helps to control the process and ensure that respective components will be remanufactured. Moreover, it also allows simple identification of which components were removed from the core and which must be replaced with new parts.

The pillars of TPM just described having a clear goal – to eliminate the 16 so-called “JPIM loss types”. These loss types were developed by the Japan Institute of Plant Maintenance and defined in a scheme to make it easier to name inefficiencies in companies. They are an essential basis of TPM and are also used in other process improvement strategies.

The 16 types of loss concern all factors that cause malfunctions and stoppages in machines and processes and are divided into three main categories:

1. Machinery and equipment
   Eight types of loss that can affect the efficiency of the production system are listed here. These are also referred to as major loss types: Equipment breakdowns, changeover and adjustment, tool change, start-up losses, short stops and idling, speed losses, scrap and rework, planned stops and shutdown.

2. Employees

These five losses concern the efficiency of human labour in the process – i.e., the working time of all employees used productively. These are Management losses (i.e., inefficient management), movement (concerns the arrangement and flow of the workplace), line organization (i.e. the coordination of production lines with each other), logistics, and measuring and adjusting during quality controls.

3. Resources
   These last three types of losses hinder the efficient use of production resources. These are energy losses (for example, when conveyor belts run unnecessarily), quantity losses (wastage of maintenance supplies such as lubricating oil), and moulds, fixtures and tools (for example, when product changes require new tools).

The previously mentioned losses also want to be measured in figures. In very modern industrial companies (also called “Industry 4.0”), this is already done automatically via process data management systems that are fed directly from machines equipped with sensors. In less modern companies, the data must be collected manually by employees.

They have a reaction plan available in Jaguar Land Rover Slovakia to anticipate situations that may arise in production and interrupt production. It is a document containing the escalation procedure, and what a given worker – operator, group leader, senior production leader, senior production leaders, and managers – should do in a given situation. According to the criteria, e.g., Problems with parts (threat of interruption of production), in case there is a shortage of parts (< 20 pieces), the document contains instructions on how to escalate and what to do specifically, i.e. assigning a task to a given worker (e.g. operator, group leader – checking the current stock inventory on the line). This greatly increases responsiveness and reduces reaction time. Thanks to this plan, leaders at different levels can react quickly in a given situation and work quickly to eliminate the problem. This reduces the time for downtime, or even prevents downtime. Thanks to the immediate reaction, the escalation is moved on to the support department, which immediately communicates with the suppliers and solves the possible consequences (non-delivery of parts, delivery of damaged parts…), which makes it possible to flexibly plan imminent shutdowns or downtimes. It is also a tool for safety awareness, where in the event of an accident there is an automatic escalation to the remaining departments, so we can prevent possible further similar accidents.

One principle of TPM is the continuous improvement of the working environment – this also requires the commitment of the employees themselves. A systematic approach that can be implemented in all areas of the company is the 5S method.

This should help to minimize all non-value-adding activities (in the sense of TPM, i.e., waste of working time) at one’s workplace (whether producing at a production line or administrating at a desk).

The five “S” are derived from the Japanese terms “Seiri”, “Seiton”, “Seison”, “Seiketsu” and “Shitsuke” – of course, you don’t have to memorize them. But they can also be translated appropriately into English: sort, set in order, shine, standardize, and sustain.

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The elements of the 5S method are as follows:

1. S like sort
   In this step, all elements that are not needed for the work should be sorted out – this should increase the clarity at the workplace and create more space for actually necessary material or work equipment.
2. S like set in orderr
   A system of all work equipment and materials is introduced, ordered according to aspects such as sequence, frequency of use or ergonomics. Markings on, for example, the tool and its storage location should help to quickly recognize deviations from the system.
3. S as in shine
   The work area should not simply be kept clean – in the course of cleaning, the cause of soiling should also be inspected and whether it can be avoided in the long term. The target condition is also compared with the actual condition of the work equipment and any deficiencies are identified.
4. S for standardised
   By arranging work equipment, markings and cleaning schedules across work areas, workplace changes should be able to be carried out as efficiently as possible (to minimize familiarization times).
5. S as in sustain
   This point essentially concerns the actions of the employees – only if they independently and conscientiously observe the rules and apply them constantly will the 5S method be successful in the long term.