| | | Where Does System Supportability Engineering Fit Into the Programme?
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During the Concept Phase the Customer's Programme Supportability Engineer (PSE) should begin to formulate the overall supportability strategy. As part of this thinking the issue of logistic analysis should be considered and, in particular, how the analysis process needs to be tailored to achieve the programme aims at minimum cost. The derivation of the overall supportability strategy should begin cognisant of the Use Study. However, the Customer (DPA) does not have a good record of providing the Use Study in a timely manner or usable format. |
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One of the most important elements of the System Supportability Engineering process is the Failure Modes Effects and Criticality Analysis (FMECA). Again, this element has fallen into disrepute because it is seen as manpower intensive, time consuming and very expensive. However, in an attempt to obtain meaningful results in a timely manner during the assessment phase, the FMECA can be tailored to provide a functional level analysis. The aims of the functional level FMECA are, firstly, to give the design team a top-level appreciation of where the design issues might lie; secondly, to provide early failure information to enable the establishment of the R&M Case; and thirdly, to provide functional level information to the safety engineers to enable the early safety analysis to begin. |
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2.2 Logistic Support Plans |
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During the assessment phase the Customer logistics managers should be developing their view of the system supportability strategy. Often these early views are poorly defined but they do guide the potential contractor to gain a limited understanding of the potential support solution. Very often heavy hints are given which can guide a contractor; however, one should never fall into the trap of offering a type of support solution, e.g. CLS, just because the Customer has hinted that this is its preferred solution. In the final analysis the support solution has to pass the Main Gate affordability test. The selection of the support solution must always be made on the basis of cost-effectiveness within a support strategy - there is more than one way of delivering CLS. |
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The MOD output at the end of the assessment phase is an ILS Plan. The contractor will be expected to respond with an Integrated Support Plan supported by the necessary ILS element plans. This is the point at which the contractor can be very smart. The ILS plan will give the MOD view of how the supportability engineering programme should be put together; however, by skilful and careful tailoring the contractor can offer alternative (and less expensive) ways of meeting the requirement. For example, the MOD may request a Logistic Support Analysis Record (LSAR). If uncontrolled the LSAR can become a millstone around the contractor's neck and there is a particularly bad example of a US contractor losing $110 million on a programme through a poorly designed LSAR. The key is to understand fully the role of the LSAR and how it will be managed in-service. The decision can then be made whether to invest in software-based tools like Eagle and SLIC or to utilise a simple spreadsheet approach. |
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One of the biggest challenges for the System Supportability Engineer arises in the design phase. As stated previously, the prime aim of System Supportability Engineering is to arrive at the most cost-effective support solution. In order to achieve this aim the supportability engineer must carry out his analysis and provide his input to the system design in a timely manner - the project manager will not allow the designer to hold up the design process while he waits for the last piece of the jigsaw from the supportability engineer. Consequently, the advice to the supportability engineer should be work quickly, accurately and effectively in order to match the pace of design progress - it is better to have some influence on the design than none because you were too slow. |
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Other activities that can be carried out in the design phase are as follows: |
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| . | Refine FMECA to system level. This can further assist the R&M and Safety Cases and assist the Reliability Centred Maintenance (RCM) analysis. |
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| . | The RCM analysis provides information to the Maintenance Task Analysis, Training Requirements and Documentation Requirement. |
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| . | The FMECA provides information to the Level of Repair Analysis (LORA), which assists Support Solution derivation through trade-off studies to provide maintenance policies, tools and test equipment and facilities plans. |
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| . | Finally, some consideration should be given to how the system is to be disposed of at the end of its service life and how obsolescence is to be managed. |
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Prior to the design review process the bulk of manufacture effort would be in any prototyping required. However, as the design begins to 'chill', as it progresses through Preliminary Design Review (PDR), the System Supportability Engineering effort increases in intensity. The major effort is in the refinement of the ILS element plans as some of the support solutions emerge. The supportability engineer should aim to have between 75 and 80% of the support solution defined by the Critical Design Review (CDR) and for it to be 95% complete by design freeze. Beyond CDR, the effort should be directed at implementing the ILS element plans and formulating the System Support Plan. The System Support Plan should contain all of the key supportability elements of the ILS plans. Whilst a System Support Plan is not defined precisely in any textbook, this is the opportunity for the System Supportability Engineer to demonstrate how effective his supportability planning process was. |
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During the manufacture phase is the time to look forward to the system entering service. The MOD will be seeking proof that the equipment is as reliable, maintainable and available as specified in the requirements documents and predicted in the R&M plan. Consequently, it may be appropriate to consider how the in-service data is to be gathered and analysed in order to provide the necessary level of assurance. Failure to consider this process may lead the MOD to invoke and In-service Reliability & Maintainability Demonstration (ISRMD), which is carried out at the contractor's expense and can become very costly. |
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As the system enters service the System Supportability Engineer can now reap the rewards from the early system supportability planning effort. In-service data should be analysed to ensure that R&M predictions are being met. Moreover, where mission failures have been experienced, the reasons for these failures must be established. Furthermore, the performance of the support solution should be confirmed by monitoring operational availability, off the shelf satisfaction rates, AOG, VOR rates etc. The Customer will challenge the availability figures if there is a perception that the system performance is below par so it is important that the Supplier understands fully how well the holistic (operational and support) system is performing. |
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As can be seen from the foregoing paragraph provision of in-service data is paramount to understanding system performance. Historically, in-service data, especially that provided by the MOD, has been unreliable. Consequently, Original Equipment Manufacturers have not been able to access sufficiently reliable data to enable them to make system improvement decisions. The advent of Product Life Cycle Support (PLCS) with its associated data exchange standard (ISO 10303 AP239) should provide the future basis for efficient data exchange within Shared Data Environments. It is still very early to judge the effectiveness of PLCS - but the aims are laudable. |
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The oil industry and nuclear power are two examples of how costly it can be to dispose of systems at the end of their service life. Much of the cost of disposal centres on satisfying the legislative requirements of system disposal and, as legislation is evolutionary, disposal costs are increasingly difficult to define. Consequently the best advice that can be given to a manufacturer is to plan for disposal at the design stage of the programme and attempt to include indicative disposal costs in the through-life management plan; however, keep your disposal strategy under constant review in light of legislative changes. |
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Figure 2, below, draws together the elements of the System Supportability effort from FMECA, with its outputs to the AR&M and Safety programmes, to the LSA element plans and the development of the System Support Plan. |
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last update: December 27, 2004 |
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