A walk around UK factories today reveals a wide variation in the quality and quantity of spare parts held for the manufacturing assets. A wide range of parts management and maintenance services exists but a complete audit of the installed base and existing stocks of spares is essential before any such agreement can commence.
The audits reveal that a surprising number of companies are unclear about the spares they hold. Some manufacturers have been found to carry more than 10 years of spare parts – in these cases it is increasingly difficult to differentiate between useful spares and scrap metal.
Even companies carrying a more realistic two to three years supply of spares are tying up working capital and wasting space that could be put to better and more productive use.
This goes a long way to explaining why the UK average overall equipment effectiveness (OEE) – the ratio of a plant’s actual output to its theoretical maximum – languishes at around 40%, while a world-class figure is 90% or above.
Because OEE measures actual against maximum output from the total asset base, any assets – including excess spare parts – that are not contributing towards useful production will drive down OEE. This in turn has a direct impact on return on net assets (RONA), determined by dividing profits by net assets, and a key measure of a manufacturer’s performance.
Leading edge manufacturers are now achieving spares stock turns of three to four times a year or better. But by integrating condition monitoring (CM), computerised maintenance management systems (CMMS) and manufacturing scheduling systems it is possible to safely reduce spare parts stocks to almost zero – without building in surplus plant capacity or risking lost production through delays in the repair or replacement of failed equipment.
Current CM technology enables manufacturers to predict, with a high degree of certainty, most equipment failures. Integrating this information with an effective CMMS means repairs are properly planned, spares are ordered from suppliers at the right time, and maintenance personnel arrive armed with all the right tools and manuals to carry out the repair in the minimum time.
By further integrating the CMMS with the manufacturing scheduling system, repairs can also be planned for a time that will cause minimum disruption to production.Zero spares holding is no longer a sign of reckless risk taking, but a demonstration of a well planned, predictive maintenance strategy – so get integrated and rid of that scrap metal!