10 months ago

Maintworld 2/2017


XXXXXX RELIABILITY What Makes a Critical Spare Part ‘Critical’ When we are working with organizations to improve their maintenance storerooms, one of the first activities we complete is defining an obsolete part and a critical part. If we can agree on those two definitions, then every part in the storeroom ought to fall within those boundaries. JOHN ROSS, Senior Consultant, Marshall Institute TIT TURNS OUT that an obsolete part is anything that doesn’t go to anything (layman’s definition), or is in excess of what is actually and practically needed. A critical spare part, however, is another thing altogether. Left unchecked and unstructured, a critical spare part is thought to be anything that will shut the plant down. Imagine, at its most basic interpretation, a critical spare part is, surprisingly, critical. To our partners in production, if not having the item when needed will lead to excessive downtime, then the part is indeed critical. But what does excessive downtime mean? “Excessive” is a very subjective word. For finance and all the folks that worry about the numbers, any part that is really expensive can be considered critical. After all, doesn’t it make sense that an important part would cost a lot of cents? Exactly how much is a lot? To small companies, $10,000 seems like a lot. To global giants, not so much. For maintenance, long lead times keep us up at night. Like downtime and costs, long lead times can be subjective. How long is long? I tell people that if you have to hold your breath until you get the part, 26 seconds is a long time. Label Items as ‘Critical’ for the Right Reasons It is important that we clearly define the attributes that make various parts uberimportant. We have to take subjective characteristics and agree on the level of significance each has, relative to the part being present in our storeroom. Convert subjective to objective. With this in mind, our exercise becomes a simple process of engaging those, who would otherwise be the victim of our process, in on the decision to classify a part as critical. The output from this team is a clear distinction of what makes a part very, very important. The group gathered will decide the characteristics to consider, the levels within the characteristics to measure, and assign a weight to each level. I suggest a group makeup of: • Maintenance hourly • Production hourly • Production supervision • Storeroom • Engineering • Maintenance supervision First, let’s examine the issue of incurring downtime. The assembled group is tasked with developing a 5-layer ‘downtime’ breakout with an associated weight. What we are constructing in this process, is a method to convert subjective to objective; an objective number whose cumulative score can be used as a cut-off to determine if a part is critical or not. This spreadsheet becomes the algorithm of our determination process. I like to call it the calculus of our critical spare parts practice. 22 maintworld 2/2017

Power Up Your Skills Open Courses in Europe Planned Maintenance Optimization (PMO) Detect and control your failure modes. Location Dates Language DE - Frankfurt 05.-07. June English NL - Eindhoven 19.-21. June Dutch NL - Eindhoven 04.-06. September Dutch DE - Frankfurt 25.-27. September German DK - Copenhagen 02.-04. October English This fast paced course is designed to assist delegates to develop an strategies and approach defect elimination in a methodical manner. This course will emphasize the PM Optimization methodology; an RCM based approach to maintenance analysis designed for an existing plant or new plant that has vendor generalized maintenance programs. Maintenance Work Management Location Dates Language NL - Eindhoven 23.-24. May Dutch NL - Amsterdam 30.-31. May English DE - Düsseldorf 30.-31. May German DE - Stuttgart 20.-22. June German DE - Frankfurt 27.-29. June English DK - Copenhagen 05.-07. September English NL - Eindhoven 12.-14. September Dutch DE - Frankfurt 19.-21. September German The key element to any operation leader’s success is having a maintenance have competent work preparers/planners that can ensure the maintenance schedules and executes the plan. Identify leading and lagging indicators Learn more and register at +31.30.799.5050