Many of our clients keep back-up pumps for the highest profile pump tasks on important sites. For low-cost pumps performing non-critical tasks it's just not worth it. The question is: at what point is it worth the extra cost?
Many property managers and engineering teams make the decision primarily based on current (and not future) budgets. Is this the best approach? Or is there another option available? Experienced operators will be all too familiar with the downsides of short-term cost cutting leading to higher whole life costs, just to try and keep within the constraints of a budget. You know what's best for the company, but sometimes it's just too hard to convince management that a slightly larger budget now will actually reduce cost in the overall. However, with the right tools at your disposal, it is possible to change that mindset.
Can any steps be taken to avoid pump failure, or to minimise the consequences of pump failure? How much do these cost? It could be more economical to carry out work prolonging the life of an existing pump than to buy a spare one.
2. Future usage
Are you planning to increase or decrease your usage of the pump in the future? How long do you expect that pump application to be required? If it's soon to be redundant then a spare isn't a good idea. On the other hand, if it's to be used a long time yet you'll have to buy a pump in the future anyway, so you could take advantage of time to find the best price for a spare pump without needing to worry about long lead times.
If you have historical information on the pump application, how long have previous pumps lasted for? Based on that information, when is the existing pump likely to fail? As experienced operators will well know, the length of a time a pump will last for varies considerably, so the best guide is the previous performance of pumps in the same application. If the last pump ran for 30 years, there's a chance the current one may do too.
As part of periodic pump inspections, assess the deterioration of the parts and keep records. This will help to predict the future life of the pump, and whether you've got plenty of running time left (or whether the requirement for a replacement is imminent, in which case it may be worth ordering a spare now).
Is the pump obsolete, or likely to become obsolete soon? Newer pumps are often more efficient, so by not buying a spare now you'll be able to have the latest and best when you eventually do replace it. On the other hand, you may want to buy a dimensionally interchangeable spare now so that you can swap the pump straight out when it fails without needing to modify pipework or other systems.
Do you have other pumps elsewhere that you could swap around to cover in an emergency? If so you may decide that this is as good as having a spare.
7. Lead time
What's the typical amount of time you'd have to wait for a replacement? How easy would it be to operate without a pump for that period of time? You may be surprised to discover that the pump is available on a next-day delivery, so it's hardly worth having a spare. Look out for Brexit increasing lead times on European-made pumps though.
8. Care of spares
How well are you able to look after a spare pump? If it's left in a dusty corner for a long period of time without being rotated, you may find that the condition deteriorates very quickly when it's installed, taking away all the advantage of having that spare pump in the first place.
It goes without saying but the list wouldn't be complete without it. How important is the pump's function? What would be the cost per hour or per day of not having it running? Non-critical pumps will probably have a much too low cost to be worth keeping a spare. Be realistic though: if it's a heating pump, you'll probably be fine in the summer, but a failure next January would be a different story.
Last but not least - when does buying a replacement fit best into your budget? If you're over your budget for this year, the cost of a spare pump could be pushed into the next year. However, if you know your budget is going to be tight in the future, perhaps it would be a better plan to buy a spare pump this year and save yourself the future cost.
So in conclusion: this is only a brief overview of the points to consider, and of course everybody's requirement is different. If you want to discuss this further though, for example to find out what the shortest lead time on a pump is in the case of emergency, please go ahead and contact us - we're here to help you in both emergency situations and your preventive maintenance planning!