Interesting article online by World Class Manufacturing provides a Critical Spare Parts Calculator and advice on the following:

• Purchasing Guildelines for Maintenance Storeroom Management
• Stock-Keeping Guildelines for Maintenance Storeroom Management
• Maintenance Storeroom Management Guildelines for Releasing Stock

 WCM suggests using the calculator which is based statical methods to optimize your maintenance inventory, and suggests whether to buy or not to buy parts.

Please note : You will need to estimate downtime costs, the failure frequency, and the lifetime of the machinery where it will be used

An image of the critical spare parts calculator 

The article concludes

“The requirement to balance keeping the parts in inventory with the need to control spending is the reason it is important to have a clear, rational, and well-understood policy.

The maintenance storeroom manager needs to know the facts regarding costs, the frequency of the need for specific critical expensive parts and the time required for purchasing them in order to keep that balance.”

The article was written OSKAR OLOFSSON by Lean and World-Class Manufacturing consultant and the founder of WCM Consulting AB.