Chapter 7. Early Equipment Management. Part 3

5.2 What is ‘MP Design’?

(1) Defining MP
Defining MP and MP design
MP is an abbreviation of ‘Maintenance Prevention’. It is defined as follows:

Activities carried out at the stage of planning and designing new equipment, to promote reliability, maintainability, economy, operability, safety etc. and minimise maintenance costs and deterioration losses, by incorporating maintenance information and new technology.

The ultimate aim of these activities is to create maintenance-free equipment. The activities can be divided into two categories: providing MP information and incorporating it into the equipment’s design.

Providing MP information means collecting and organising knowledge about problems identified in the course of operating or maintaining existing equipment, and how they were resolved. In other words, it means finding out about improvements made to existing equipment, and feeding this knowledge back to the design department in a readily-usable format, so that it can be used to improve the design of new equipment.

This is important, because, as everyone knows, most advances in equipment technology have resulted from improvements made to correct problems or shortcomings in existing technology.

Today’s production machinery and process plant have become so large that a single operational error can have a major negative impact on the local and even the global environment. They have also evolved into systems that operate round the clock to produce high-precision products. This means that bad equipment design decisions can jeopardise a company’s future, so equipment designers need to stay closely in touch with reality, and be careful not to get carried away by their own ideas. MP information provided by the operating and maintenance departments should be fully incorporated into the designs, and the design process should be aimed at ensuring trouble-free operation right from the outset.

Defining MP design

Equipment design aimed at minimising LCC is called ‘MP design’. It was originally defined as follows:

The goal of MP design is to minimise the equipment’s life-cycle cost, or LCC (the total cost of the equipment over its entire life-cycle, i.e. the sum of its acquisition costs and running costs). The design approach in which the equipment’s LCC is included in the design specification along with its functionality, reliability, maintainability and so forth, is known as ‘LCC design’. MP design is the technical manifestation of LCC design.

In TPM, this approach to MP design is expanded, and the term ‘MP design’ is used to mean a design philosophy pursuing efficiency to the extreme, by focusing not just on reliability and maintainability, but also on preventing all other losses that tend to drag down the efficiency of the production system.

(2) The importance of MP

To create equipment that itself can assure product quality, the causal relationship between product quality and equipment precision needs to be made explicit. The design philosophy that aims to do this is called ‘design of core equipment functions’. However, the precision of the equipment will deteriorate over time, so it needs to be quantified and periodically restored to its original level. Reversing deterioration is principally the role of the operator. The aim of MP design is to make this role as easy as possible.

The temptation for the equipment designer is to focus on the equipment and its intrinsic reliability, and thereby lose sight of the operator’s role in operating the equipment. Consequently, the operator’s role ends up being dictated by the equipment. In other words, the operators have to modify their behaviour to suit the needs of the equipment. This might be acceptable in theory; but in practice, it tends to make life very difficult. And if it becomes difficult, or even impossible, to uphold maintenance standards, it will also be impossible to sustain the equipment’s core functions.

As Figure 7.22 illustrates, there is a trade-off between maintenance skills and the MP function.

Figure 7.22 The Concept of MP Design

Pattern A results in a design highly dependent on maintenance skills, while Pattern C aims to lighten the maintenance burden by strengthening and enhancing the equipment’s MP functions. Ideally, MP design should be pitched correctly for the actual level of equipment maintenance skills possessed by your company.

(3) MP requirements

1)  Minimise the amount of breakdown maintenance generated by the equipment. In other words, design for higher reliability (i.e. a long MTBF (Mean Time Between Failures)).

2)  Design the equipment so that any breakdown maintenance generated by the equipment can be handled more efficiently. In other words, design for high breakdown maintainability (i.e. a short MTTR (Mean Time To Repair)).

3)  Design the equipment so that any preventive maintenance it requires can be handled more efficiently. In other words design for high preventive and autonomous maintainability.

4)  Design the equipment to facilitate CBM (condition-based monitoring). In other words, design for high diagnosability.

5)  Design the equipment to be safe and easy to operate.

Table 7.9 shows the basic attributes that should be covered by MP design. Table 7.10 shows the principal items that should appear on MP design check sheets, while Figure 7.23 shows a typical checksheet. Figure 7.24 enumerates the equipment design issues covered so far.

Table 7.9 MP Design Attributes

Table 7.10 Main Contents of MP Design Check sheets

Figure 7.23 Typical Check sheet

Figure 7.24 Table of Equipment Design Issues

6. Implementing Early Equipment Management Step by Step

6.1 The 7 steps for rolling out an Early Equipment Management system

As Figure 7.25 shows, in a typical Early Equipment Management system, the process from planning until commissioning is split into seven steps. A comprehensive design review (DR) should be performed at each step.

The first three steps, which constitute the planning stage, are especially important.

Step 1: Concept planning

Step 2: Action planning

Step 3: Design

To accomplish these steps, start by drawing up a Quality Assurance (QA) matrix. Next, carry out a 4-M analysis. Finally, perform a process FMEA. If you have the people with the relevant knowledge go through the design with a fine-tooth comb at various stages beforehand, fewer minor equipment defects will emerge during and after the witnessed test-run, and the commissioning period can be shortened.

The length of the startup period, from when the equipment is installed until it is in stable operation, is one of the elements that increase or reduce the LCC. Technology today is moving so fast that falling behind production schedules can have a major impact on business. This is why MP design explicitly addresses the challenge of reducing equipment efficiency shortfalls and commissioning control costs arising during startup. Commissioning control is regarded not as a separate entity, but as part of the equipment’s LCC.

The purpose of design reviews is to catch any problems that have slipped through the MP design net, so that they are not carried over to the commissioning stage. This ensures that once the equipment has been installed, an immediate, ‘vertical’ startup can be achieved. In other words, instead of leaving the identification of problems to the commissioning stage after installation and adjustment, thorough design reviews are carried out before installation.

As Figure 7.26 shows, the design reviews at each stage can be ranked in descending order of importance as follows: (1) design, (2) fabrication, (3) witnessed test-run, (4) installation. This underlines the crucial importance of the review carried out at the design stage.

6.2 Step 1: A typical planning stage

Step 1 is the crucial stage at which the equipment plan is formulated and finalised, based on the company’s annual and mid-term business plans. In general, companies tend to put the cart before the horse, and give too much weight to the budget framework. Estimates are made without examining the proposals thoroughly enough, and it often proves necessary to correct the details, the amount budgeted, the time-frame and other parameters after the budget has been decided. To avoid this scenario, MP design aims to achieve higher planning precision by focusing on the following:

(1)  Equipment engineers should get involved early in the product development or improvement process (from the conceptual design stage on) and already make a start on designing the equipment.

(2)  To this end, the purpose and necessity of the investment should be made explicit, as should the economic requirements the equipment must satisfy (in terms of LCC and LCP), and more than one proposal should be considered.

Figure 7.25 A Typical Early Equipment Management System

Figure 7.26 Design Review and Startup Period

(3)  Estimate the cost benefit of each proposal

(4)  A design review should be carried out by knowledgeable staff from the relevant departments. This design review should include a thorough investigation of the appropriateness of each proposed investment, its future potential, the degree of technical difficulty it presents, its necessity, how economical it is, the order and schedule in which it should be carried out, and so forth. Only after all this information has been carefully clarified should the most appropriate proposal be selected. Prototypes fabricated on experimental equipment should then be assessed, and technical information from internal and external sources regarding this and similar equipment should be carefully studied in order to flesh out the proposal to be implemented. Figure 7.27 shows an example of a proposal comparison table prepared at this stage.

Figure 7.27 A Typical Investment Proposal Comparison Table

6.3 Step 2: A typical action planning stage

Once the equipment investment plan has been approved, it is time to decide on the equipment design and fabrication specifications, based on the investment proposal comparison table drawn up in Step 1. When this has been done, the second design review should be used to check that none of the items in the equipment design and fabrication specifications has been overlooked. The design and fabrication specifications should then be incorporated into the equipment concept, improving the precision of the design (see Figure 7.28).

Figure 7.28 Detailed Flow Diagram of Action Plan

The analyses used in the action plan can be described as follows:

(1) Process Diagram

This clarifies the sequence and limits of each process.

(2) Process QA matrix

This clarifies the relationships between product quality and process. Figure 7.29 shows a typical QA Matrix.

(3) 4-M Analysis

The Process QA Matrix may show that certain processes are heavily implicated in the generation of defectives. In this case, the 4-M Analysis will show how these defects relate to the 4 Ms, and will clarify the equipment conditions needed to stop them from being produced. Figure 7.30 shows a typical 4-M Analysis.

(4) Process FMEA

The Process FMEA further quantifies the degree of risk posed by the problems identified in the 4-M Analysis. This information is very useful in evaluating the equipment concept. If any item fails to meet the assessment criteria, the issue should be addressed, and a re-evaluation carried out. Figure 7.31 shows a typical Process FMEA.

(5) Record of Corrections Made to the Equipment Design, and Action Taken

Problems thrown up by assessing the equipment specification concept and carrying out the second design review should be carefully addressed in the equipment design specifications, using a form of the type shown in Figure 7.32.

Figure 7.29 Process QA Matrix

Figure 7.30 4-M Analysis

Figure 7.31 Process FMEA

Figure 7.32 Record of Corrections Made to Equipment Design, and Action Taken

6.4 What happens at the design stage

The design stage covers the period from receiving budget approval to just before embarking on fabrication.

(1) Formulate the basic design, based on the equipment specification, and draw up the implementation budget.

At this point, an equipment FMEA (see Figure 7.8) should be carried out to find out how the system operation, safety, product quality and other parameters would be affected if a failure were to occur in an equipment system, subsystem, or section. Any problems identified should be addressed in the design. Equipment layout considerations should also be thought through in depth at this stage. Typical considerations include the format in which raw materials will arrive; where they are to be stored and by what route they should be conveyed to the production line; how the power and other utilities are to be supplied; and how the finished products are to be packaged, stored and shipped out.

(2)  In the design review carried out after formulating the basic design, check that nothing has been overlooked regarding the equipment’s reliability, maintainability, operability, safety, economy, flexibility and conceptual design requirements. The next step will be to flesh out the basic design.

(3)  Building on the basic design, formulate the detailed design. At this point, an FMEA (see Figure 7.15) should be carried out on the equipment’s components. Besides improving the reliability of the parts, this process includes examining their factory- friendliness, and making any necessary changes to the detailed design. To ensure that MP information is not overlooked, make full use of available design standards, collections of design expertise, and common specifications. This will help to make the design as precise as possible, and eliminate the individual differences that tend to creep in when many designers are working on a project.

This is the stage of the design process at which you will need most outside help from construction companies and other specialist firms. It is important to conduct the design review very thoroughly, based on a relationship of trust between all concerned, and underpinned by the knowledge and experience of all parties.

(4)  In the fourth design review, after the detailed design has been formulated, have the members of staff directly involved – in the maintenance, manufacturing, safety, environment and technology departments – get together and work up the design, making sure that nothing has been overlooked with regard to the basic design requirements concerning reliability, maintainability, operability, safety and other attributes.

6.5 An overview of MP design at Steps 2 and 3

(1) Defining MP design

Maintenance Prevention (MP) design is the set of activities carried out to ensure that when new equipment is introduced, it will be highly functional, easy to use (adaptable and easily operable), resistant to failure, and maintenance friendly, and that its life-cycle profit (LCP) will be maximal, based on a forecast of the future of the products it is to produce. The weaknesses of existing equipment are studied, and the resultant knowledge is fed forward into the design of new equipment with the aim of making it more reliable and maintainable, and ultimately maintenance-free.

(2) The aims of MP design

MP design aims to break free of the constraints of equipment-centred design and focus instead on optimising the operator-machine relationship. It seeks to do this by creating maintenance-free equipment whose high quality, high productivity and safety is assured, and whose LCP is maximised, enabling the equipment to accommodate future needs.

In the MP design carried out during Steps 2 and 3 of the overall design process, activities aimed at building-in quality are of the utmost importance.

(3) The basic equipment prerequisites

When carrying out MP design, the basic attributes required of the equipment (such as reliability, maintainability, autonomous maintainability, operability, resource economy, safety and flexibility) must be defined in concrete terms. However, these terms tend to be used rather loosely; ‘reliability’ for example, can mean different things to different people. Table 7.11 gives their definitions.

Table 7.11 Equipment Prerequisites and Their Definitions

(4) Collecting and using information

MP design requires a system enabling information about daily operating and maintenance activities to be collected and compiled in a standard format, as shown in Figure 7.33. Many design standards are a good example of how information tends to mount up to such proportions that it becomes hard to understand, difficult to search, and easily outdated, and consequently not exploited effectively. Once design standards have been formulated, that is not the end of the matter: it is essential to keep revising them in the light of new information, and keep trying to make them more user-friendly, even as you make use of them in the current design project. It is also vital that items common to all equipment should be standardised on a common specifications sheet, and incorporated rigorously into the standards used for designing and purchasing new equipment. It goes without saying that check sheets should also be drawn up, and checks should be carried out at every stage. Tables 7.12 to 7.15 show examples of the principal check sheets.

Figure 7.33 Flow Diagram for Collecting and Using MP Information

Table 7.12 Equipment Safety

Table 7.13-(1) A Typical MP Checklist

Table 7.13-(2) A Typical MP Checklist

Table 7.14 Specifications Checklist (Measurement and Control)

Table 7.15 Specification Checklist (Mechanical Design)

6.6 Steps 4 to 7: fabrication, manufacturer’s test-run, installation and commissioning

(1) Step 4: Fabrication

In this step, the equipment is fabricated in accordance with the detailed design. The principal dimensions and progress against schedule should be checked at intermediate stages in order to raise the reliability of the fabrication process.

(2) Step 5: Manufacturer’s test-run

In this step, the manufacturer tests the equipment under load. Problems identified up to and including Step 4 are solved, and fresh issues are identified and measures taken to eliminate them before the equipment is delivered. In short, every effort is made to ensure that no trouble will arise once the equipment has been set up at its final destination.

Particular attention should be given to making sure (using checksheets) that the MP information on the Common Specifications Sheet has all been incorporated into the equipment. It is very helpful to have operators and maintenance technicians participate in the process at this stage.

(3) Step 6: Installation

The managers, supervisors and other key personnel in the department that will be using the equipment should now be consulted regarding the installation schedule, and any necessary adjustments should be made. The reliability of installation should also be raised by checking the equipment carefully against the design diagrams as it is being installed.

The test-run is then carried out in cooperation with the key personnel. Careful checks are made to ensure that the design requirements have actually been met, and remaining problems are identified and corrected. Products are produced on a test basis, and checked to see whether they come up to quality targets. The equipment is also evaluated to see whether its parameters meet their target values. Manufacturing conditions and work standardisation will need to be given careful consideration ahead of time.

(4) Step 7: Commissioning

At this step, the production department takes over and monitors the process capability while manufacturing the product.

If equipment problems have already been comprehensively addressed and corrected, they are not carried over to this stage, so vertical startup can be achieved and the equipment can attain 100% of the target values on the basic specifications sheet within a relatively short commissioning period.

(5) Recording problems detected in the period from intermediate inspection to test-run, and during commissioning

Details of all the equipment problems discovered should be recorded, their causes identified, countermeasures devised and implemented, and the results assessed. Figure 7.34 shows a typical record of this process. Such problems arise because of failure to build one hundred percent quality into the equipment at a previous stage of the Early Management process, so it is important to work out how to stop the same problems from happening again, and find ways of improving the Early Management system.

Figure 7.35 is a typical commissioning control flowchart. Its first striking feature is that several departments work together to carry out the commissioning, with clearly- demarcated roles allocated to the department that will be using the equipment, and to the maintenance and planning (or design) departments. Commissioning control is the point at which design, operation and maintenance meet, so a system of this sort is obviously essential if the process is to run smoothly. The second striking feature of this example is that the initiation and termination of commissioning control are clearly defined. The parameters for deciding whether to terminate or continue commissioning control (such as production capacity, stoppage frequency, stoppage severity and defect rate) are specified when commissioning control is initiated.

Finally, Figure 7.36 shows a typical Commissioning Control Notification Sheet.

Figure 7.35 Flow Diagram for Commissioning Control

Figure 7.36 A Typical Commissioning Control Initiation and Termination Notice

Chapter 8. Quality Maintenance. Part 1

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