What is inventory control?

Inventory control, sometimes known as stock control, is the control of the spare parts inventory that your maintenance team has on hand. It’s important because it ensures that you have enough inventory for your maintenance tasks and that you don’t buy too much inventory in advance. Sometimes inventory can sit for too long, making parts obsolete or no longer useable. Using an inventory control system is key to ensuring that your parts get used at the right time.

What is an inventory control system?

Inventory control systems help ensure the right amount of inventory is available at the right time. These systems can be manual or automated. A parts forecaster is part of inventory control. It’s a tool that predicts what parts you need to purchase for upcoming maintenance. A parts forecaster can:

  • Make purchasing recommendations that consider predicted parts usage.
  • Analyze all historical parts and maintenance data in a CMMS, to accurately predict upcoming parts usage to avoid the risk of stockouts.
  • Spot patterns in your maintenance practices, like seasonal trends, and base part orders around it.

There are two main types of inventory control systems: Periodic inventory systems and perpetual inventory systems.

Periodic inventory systems

Periodic inventory systems are used to track inventory levels and adjust orders. It’s based on the physical inventory counts, and information is updated when a physical count is conducted. The count is based on a predetermined time period, such as every month, quarter, or year. The periodic system uses an average of the previous time periods for the current period. For example, if you want to know how many parts to order for maintenance in May 2023, you would take the average of March 2021 through April 2022 and use this number as your target level for May 2023 (assuming no changes to production volume, machine specs, or asset health have occurred in this time).

Perpetual inventory systems

Perpetual means that your computer program manages inventory counts automatically (although humans will still do regular inspections). For example, if you use a part on a piece of machinery, your stock level will update in real-time. Alternatively, if you order more parts for your facility, the new stock is received and updated automatically on the system.

What are the benefits of using an inventory control system?

An inventory control system allows you to make informed decisions about how many parts you need on hand at any given time. Here are some of the benefits of using an inventory control system:

  • You can reduce costs by ordering parts only when needed, rather than buying large quantities that may not be used for a piece of machinery.
  • You will have better quality control over parts so that they don’t sit for too long and potentially get damaged or become obsolete.
  • You will be able to plan for future scenarios based on historical data, this is often referred to as kitting. For example, if a part gets replaced every three months as part of routine preventative maintenance, you can build these histories into your system and have the parts ready ahead of time.
  • You will have a better accounting record. Keeping a record of your inventory on hand is not only important for managing your assets, but it also helps keep you organized in the event of a financial audit.

Inventory control vs. inventory management

Inventory control and inventory management are two terms that are often used interchangeably, but they have very different meanings. Below is a table that illustrates some of the differences:

Inventory control

Inventory management


The day-to-day counting and tracking of items on hand, and as they pass through your facility

The forecasting of items and deciding which items should be purchased, when, and in what quantity

Assists with

Tracking how many items remain in stock, and whether or not you have enough parts to match the needs of your maintenance schedule

Ensuring you have enough stock ahead of time to satisfy the needs of your maintenance schedule, but not so much that you are wasting money on excess inventory


To track how many parts are in stock for each asset, and if they are in good working and useable condition

To be responsive and predictive to demand, and to assist in managing the relationship with part suppliers

Systems used

An inventory control system like periodic or perpetual

A maintenance inventory system like: MRO inventory management software, a computerized maintenance management system (CMMS), or enterprise asset management (EAM) software

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Inventory control is key for day-to-day operations

Inventory control is a key part of maintaining your assets and ensuring that they are always running smoothly. It helps to ensure that the right amount of inventory is available at the right time and reduces waste. Discover how to get the right parts, at the right time, for the right price with Fiix’s parts and inventory management features.

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