MRO Practices

MRO maintenance storerooms have been effective at providing everything from dust masks and gloves to repair parts to critical spares. All of them useful and necessary items in an industrial facility. This is a series that will examine what would happen if we changed our thinking about MRO storerooms and started seeing them as assets, rather than expense centers to be reduced. We aren't against managing expenses and have written about reducing inventory levels and costs.

Why equipment BOMs matter in your MRO storeroom

In this post we're looking at one facet of the MRO storeroom that's essential to an asset-based approach to management: the Equipment Bill of Material. There are various kinds of BOMs which are outside the scope of this post. The equipment BOM can be a single level document, meaning that all parts used in a given piece of equipment are listed, including the quantities needed for a complete rebuild. A multi-level BOM is a more effective asset management tool in that it breaks down components and sub-assemblies. This is important because maintenance procedures are typically geared toward repairing components and sub-assemblies more so than entire pieces of equipment. The example of a multi-level BOM below provides the detail needed to support more effective maintenance procedures.

Equipment BOMs don't live alone on a maintenance island. They are useful tools to help manage preventive and predictive maintenance activities and the parts needed to support ongoing maintenance. In the real world, equipment BOMs are typically part of an asset management system. They are the part of a system most often used by maintenance personnel. Equipment bills of material are very popular with maintenance and are or should be tracked by storeroom management.

Equipment BOMs - part of an asset-based storeroom

An equipment BOM contains vital parts information needed for maintenance and repair, including information on "where used." This means that all machines or equipment where a given part is used are reflected in the EBOM and stored in the CMMS. Because simple parts are often used in multiple machines, where-used information helps assure adequate stock levels of these parts. In the real world, we have seen a specialty fastener, screw, fitting or other part used in many different machines throughout the facility. Failing to keep adequate levels of these parts can spell the difference between a timely repair and unnecessary downtime. All of those considerations make an equipment BOM a vital link in an asset based management system.

A typical BOM will include but is not limited to the following categories of information. Your facility will have unique information requirements that should be reflected in the BOM. Starting with what's stored in your CMMS or ERP system will give you a good place to begin build or updating BOMs.

Where to Start:

• • Listed assets have a part number . This number can be related to a higher level typology as in a "parent/child" structure or not depending on the architecture of the maintenance management system.

  • Every part number has a description. The description can follow a systemic approach that conforms to a standard classification system, or it can be plant-specific.

  • Manufacturer part number and distributor part number , if relevant, are also listed. Your procedure may include one or the other depending on local practice.

  • " Where used" data indicates other equipment where that part is also used. This information is correlated in the CMMS system.

  • Each part has a standard cost. That information would typically be the amount your facility pays for the part at the time the BOM was created.

  • Unit of measure for the part is included. This can be unit count, size or other relevant data.

  • Other information such as ABC classification or criticality assessment rating can also be included. Whether this data is present will depend on your local practice.*

The reliability engineer typically creates the EBOM so as to relate plant equipment to factors such as criticality, asset priority and other factors. So, if your plant is using EBOMs it's useful to know where maintenance and storeroom management responsibility begins and ends. If your equipment BOMs could stand a review, now is the time to start with the most critical equipment first. Reliability engineering, plant management and maintenance have a stake in this activity.

Need help getting your storeroom under control? Contact us at ISTeam@EECO-net.com, or call 800.993.3326.