Up Time Magazine - December 2008/January 2009 - (Page 44) precision maintenance upload Squirrel Stores & Why You Would Be Nuts to Keep Them by Phillip Slater Breaking the locks was the only option. It was 2:00am and Line 1 had stopped completely. The good news was that we knew exactly what the problem was and how to fix it. We also knew that the spare part we needed had been in the storeroom earlier in the day – I had seen it there myself. The bad news was that it was no longer there. And although we didn’t know with certainty where the part was, we were pretty sure that one of the dayshift crew had taken it and put it in his locker. Waiting was not an option so locks had to be broken. We just hoped that we found the part before doing too much damage. Second, more than just being inconvenient, not having the spare part can be a real hassle. If the plant is down at 2:00am, it’s your job to fix it and there is no spare, then you get the hassle from production – even though it is not your fault. Better to avoid all that and keep your own little emergency squirrel store – just in case. A third reason is a rationalization that squirrel stores improve service (or at least reduce downtime) by reducing the time needed to go and get the spare from the official store. Squirrel stores are usually held closer to the plant (or at least closer to the team member) than the official store, hence, the time to access the store is reduced. No matter what the reason, squirrel stores are ultimately a cultural issue, and they need to be managed on that basis. This requires building trust in the system, communicating the negative impact of ‘squirreling’, modeling and encouraging the right behavior, and not allowing any exceptions. Now, how do squirrel stores really impact your inventory levels, operational expenditure, and reliability program? And why would you be nuts to allow your team to keep squirrel stores? Here are six reasons: 1. You Will Hold More Inventory Duplicating the parts being held in your official store by holding parts in a squirrel store obviously adds to your inventory but it is the flow on effect that can be much, much worse. You might be surprised to realize that in addition to duplicating your inventory, squirrel stores can also significantly increase the level of spares held in your official store. How? Through a mechanism that I call Induced Demand Volatility (IDV). S ound familiar? This scene is played out in maintenance workshops all over the world. Maintenance team members take parts and put them away in their own stores and sometimes, when really needed, the part cannot be found. The team members do this either because they think it is ‘convenient’ or that it ‘saves time’. Convenient and time saving for them but what about the rest of us! Let’s face it, reliability and maintenance people are different. They have a unique position in the world. We all know that when things go wrong maintenance gets the blame. But when things go right, production gets the credit. As a result, some maintenance folk hoard spare parts, like squirrels keeping nuts for the winter. That’s why these unofficial stores are often referred to as ‘squirrel stores’. Look around almost any workshop and you will find spare parts that are being held in private stores, ‘just in case’. The problem with this, as demonstrated above, is that when parts are held outside of the official storeroom or inventory management system, they actually impact the rest of your inventory holding for that part. Not only in the obvious ways of poor availability and access, but also in less obvious ways relating to inventory levels, operational expenditure and even your reliability program - more on that in a moment. First, let’s understand why these stores exist. One reason is trust. That is, the trust that your official store will actually have the required parts when they are needed. If your storeroom management is unreliable, this erodes trust in the system. Also, if team members know that other team members are ‘squirreling away’ parts then they might do the same – just in case. No one wants to be caught short. Not only does it let the plant down but it is personally inconvenient. 44 december/january 2009
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