The Importance of a Spare Parts System in Manufacturing

by Fritz Seager

Numerous factors come in to play when a company tries to maximize the productivity and profitability of their manufacturing process. Capital investments, training of personnel and raw material purchases are only a few of the areas that require both careful planning and continual oversight to ensure that the company can remain competitive and profitable. Unfortunately, there is another important facet of production that often seems to be overlooked: maintaining an adequate spare parts inventory.

Control system parts
Control system parts

The importance of a well thought out spare parts system in the production environment can't be overstated. Obviously, having the correct parts on hand gives a much greater chance at eliminating unwanted downtime. Looking at the issue in greater detail, however, reveals just how costly unplanned downtime can become. Besides the direct expense of having a machine out of production, one must look at the associated cost of how that machine being out of service for an extended period of time can affect other areas of production, both upstream and downstream in your process.

As an example, let’s look at a typical polystyrene foam plant like ours. In the case of an extruder going down for unplanned service, a slight delay may not affect the supply of roll stock that is constantly being delivered to the thermoforming department. However, if extrusion needs to wait for the delivery of a replacement part, a delay of days, or longer, may severely impact the ability to supply thermoforming with foam rolls. Suddenly, the thermoforming department is also shutting down machines due to a shortage of material.

Conversely, if the plant has a thermoformer go down for an extended period of time, the extrusion department may begin to outpace the rate of thermoforming production. The result would be a sudden surplus of roll stock, increasing the strain on warehousing operations as the supply of foam rolls begins to exceed the plant's storage capacity, quite possibly even forcing an unplanned shutdown of the extruder. Obviously, neither of these scenarios is desirable when trying to balance the productivity of these two important departments, as downtime in one area can impact the entire plant.

In addition to the examples given above, there are other potential costs to having an insufficient supply of spares in the plant, including the expense of expediting delivery of a required part, the cost of having idle employees with no machine to run, and the risk of unknowingly creating a safety hazard by implementing an improper repair to try to get the machine back in to production without the correct part.

Another significant consequence of unplanned downtime can be missed or late deliveries to the customer. This is most likely the worst possible outcome, as good client relations are the lifeblood of any manufacturing organization. While it is never desirable to miss a delivery, it can be particularly frustrating when it occurs due to something avoidable, like having a basic supply of spare parts on hand.

Now that we recognize some of the potential issues that can be caused by an inadequate supply of spare parts, you may want to evaluate the current state of your parts inventory. Starting by identifying which machines have a compounding impact on production can help prioritize your spare parts strategy, as that is the equipment that you can least afford to have out of production. Continue from there with your other machines, focusing on those which may not have redundant capacity. Older equipment is another area to concentrate on, as replacement parts can become difficult to obtain, particularly on short notice.

We will discuss more aspects of spare parts, including determining stock levels, part storage, and the resupply process in future blog posts. In the meantime, feel free to contact Commodore with any spare parts questions or requirements that you may have.