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The goal of Professional Maintenance is to set up a high-performance maintenance system that will increase the availability of equipment while reducing costs to keep them up to date.

Introduction

Professional Maintenance aims to set up a high-performance maintenance system that increases the availability of equipment while reducing costs to keep it up to date. Here we find the same principles and tools as the TPM and in particular the Pillar 3 of the TPM : Scheduled Maintenance.

Like the other pillars of the WCM, it unfolds in 7 steps that we develop below.

1 – Eliminate obvious breakdowns

At first, we will start by restoring the basic conditions. More generally, it will be enough to eliminate “coarse” faults and other obvious uses which generate the premature wear of the equipment. In detail, the WCM methodology asks :

1. Set up and save EWO by equipment.
2. Schematize the equipment and cut it out as a subset.
3. List the necessary parts by subassembly. This list must specify the references, the quantities and the frequency or the criterion of change thereof (example: change of a transport chain every 100,000 cycles): the challenge is to make a 5S in the parts list and make sure we have the wear criteria that allow us to plan the parts change.
4. cClassify the criticality of equipment according to the PDPC model (see Table 1 below). It is noted that to perform this rating, the indicators MTTR et MTBF are necessary.
5. Identifier the type of maintenance according to the table Maintenance typology below.

Table 1: PDPC Model Assessment

 Machine Problem Mean Time To Repeat (MTTR) – P Level of influence on Cost / Security / Environment / Production. – D Mean time between failures (MTBF) – P Need to stop production PDPC 5 being the greatest time. 5 having the greatest influence 5 being the highest probability 5 having the necessary downtime the biggest. P * D * P * C

PDPC rating

 Very critical Critical Not very critical Not critical PDPC Score + de 590 pts + de 500 pts + de 150 pts – de 150 pts Class AA A B C

Table of maintenance typologies VS PDPC

 Very critical Critical Not very critical Not critical Class AA A B C % theoretical equipment in this class 5 à 7% 7 à 20% 35% 40% and more Type of maintenance Special preventive maintenance Preventive maintenance of 1st level Preventive maintenance of 2ndlevel Corrective maintenance Consists of Complex conditional and predictive maintenance. Conditional and normal predictive maintenance. Predictive and curative maintenance. Only curative maintenance. Inspection Very detailed Detailed Simple Without Management of spare parts Yes Yes Yes No Lubrication and basic maintenance Yes Yes Yes Yes

2 – Analyze breakdowns

Once this first stage is reached, we can start the investigations on the various breakdowns. For this, the WCM offers several ways :

1. Start by analyzing the history of EWO
2. Rely on the TWTTP and the HERCA pto identify the human causes of the problems. We can also use other tools of the problem solving as the FTA or the PM Analysis.
3. Pilot investigations in a logic PDCA.

Of course, unless otherwise specified by the management, we will start with equipment classified AA, then A, then B and finally C.

3 – Establish preventive maintenance standards

At this stage, much has been learned about the operation and proper use of equipment. We will be able to begin to develop the maintenance standards and put in place the 5S. Based on the documentation of the manufacturer and the knowledge gained, we will build documentation on the various interventions maintenances that we must lead. We will be able to use training videos showing how to disassemble and replace parts.

4 – Extend the service life of equipment

Through a good control of our equipment and a good knowledge of the needs and uses that we have of them, we will implement improvements to extend the life of the equipment. We can play with the materials, shapes, dimensions … to increase the reliability.

5 – Set up preventive maintenance

Like the TPM, we will put in place phase 3 of planned maintenance pillar. We will help with the manufacturer’s documentation and our knowledge to implement the systematic replacement of parts.

It also implies that you have to organize a spare parts store and a supply system to ensure the availability of the right references at the right time..

We can rely on the method of RCM2 to define the right strategy to adopt according to the type of problems to which we are subjected. There are other methods that we have detailed in the Scheduled Maintenance pillar.

6 – Set up predictive maintenance

This is the same stage as phase 4 of the pillar scheduled maintenance of the TPM. It will consist of putting equipment under control to predict failures and thus anticipate them.

Its implementation will require the use of important means of analysis. We can go through vibration analysis, the use of high speed camera…

7 – Manage maintenance costs

As we improve our equipment control, we will reduce maintenance costs.

The diagram below highlights the fact that the more planned maintenance is effective the lower the cost of repair and breakage. The challenge is to find the optimum between the cost of preventive maintenance and the cost of repairs.

Source

F.S. Nowlan, H. F. Heap (1978) – Reliability Centered Maintenance

H. Nishinaga (1999) – Construction of a System for Efficient Predictive Maintenance

H. R. Steinbacher, N. L. Steinbacher (1993) – TPM for America: What It Is and Why You Need It

T. Wireman (1991) – Total Productive Maintenance – An American Approach