A maintenance team needs to replace a failed bearing in a production pump. The inventory system shows that several bearings are available. However, the team cannot confirm which bearing matches the pump’s model and operating requirements.
The technician checks an old work order, the storekeeper searches through part descriptions, and procurement contacts a supplier. Meanwhile, the pump remains out of service.
The spare part may already be in the storeroom. The real problem is that nobody has a reliable connection between the asset and the part it needs.
This is what happens when asset bill of materials (BOM) relationships are missing. Companies may track spare parts by item number and quantity, but without knowing which assets use them, inventory information becomes less useful for maintenance planning.
When Inventory Exists but Equipment Requirements Are Unknown
An asset bill of materials is a structured list of components, assemblies, and parts associated with a specific piece of equipment. It helps maintenance teams understand what an asset contains and which spare parts may be needed to maintain or repair it.
For example, a pump may contain a motor, coupling, bearing assembly, seal, and impeller. Each component can have its own part number, specifications, and replacement requirements.
The relationship between the asset and these components is important. A component may be used in several assets, while another may fit only one equipment model or configuration.
What is an Asset-BOM Relationship?
An asset-BOM relationship connects an asset to the parts and assemblies that belong to it or are required to maintain it.
A simple structure may look like this:
Pump P-101 → Bearing Assembly → Bearing Part No. BR-204
This relationship tells the maintenance team more than the fact that BR-204 is available in inventory. It indicates that the part is associated with a specific asset.
A well-maintained BOM may also include quantities, manufacturer details, approved alternatives, component revisions, and compatibility notes.
Why a Flat Spare-Part List Is Not Enough
A general inventory list can show:
- Part number and description.
- Available quantity.
- Store or bin location.
- Supplier details.
- Purchase cost.
However, it may not show which equipment uses the part, how many units are required, or whether the part is suitable for a particular asset.
Consider two bearings with similar dimensions. One may be suitable for a low-speed conveyor, while the other is designed for a high-speed pump. If the asset relationship is missing, a technician may select the wrong item based on its description alone.
Inventory answers the question, “What do we have?”
An asset BOM helps answer, “Which equipment needs this part, and is this the correct component?”
Both types of information are necessary for effective spare-parts management.
How Missing Relationships Create Problems Across the Spare-Part Lifecycle
A spare part moves through several stages before it supports a repair. It may be identified during maintenance planning, purchased, received, stored, reserved, and eventually issued to a technician.
Missing asset-BOM relationships can create problems at every stage.
Maintenance Planning Starts With Guesswork
A planned maintenance task may require specific components, but the planner cannot confirm the correct parts without a reliable BOM.
The team may need to review equipment manuals, contact technicians, or search through old work orders. This takes time and can make maintenance planning less predictable.
The problem becomes more serious during shutdowns or major maintenance activities. If a required component is missing, the team may have to delay the work or extend the equipment downtime.
For example, a maintenance team may plan to overhaul a compressor but discover during the job that a required seal kit was not included in the original parts list.
The maintenance task was scheduled. The equipment was available. Yet the work could not proceed as planned.
Purchasing Can Order the Wrong Part—or Too Many
When procurement teams do not have clear asset and component information, they may rely on old purchase orders, supplier descriptions, or informal communication with technicians.
This can lead to:
- Incorrect part specifications.
- Duplicate purchases.
- Unapproved substitutions.
- Longer supplier clarification cycles.
- Excess inventory created to reduce uncertainty.
A buyer may order a component that appears similar to the required part but does not match the equipment’s actual configuration.
The opposite can also happen. A company may purchase more parts than necessary because it cannot identify which assets already have suitable spares available.
Missing relationships make it harder to purchase with confidence.
Stores Teams Struggle to Issue the Correct Spare
A part can be physically available in the storeroom but still be unsuitable for the requested repair.
Storekeepers may need to ask technicians for confirmation or search through equipment documentation before issuing the item. This can slow down the maintenance process, especially when several parts have similar descriptions.
There is also a risk of issuing an incompatible component. If the error is discovered only after installation begins, the team may need to stop work and arrange another part.
A clear asset-BOM relationship helps stores teams connect a maintenance request to the correct component and its inventory details.
Criticality and Stock Decisions Become Less Reliable
Not every spare part has the same impact on operations.
A component used by several critical production assets may deserve more attention than a part used by one low-impact machine. A part with a long supplier lead time may also require a different stocking strategy.
Without asset-BOM relationships, companies may struggle to understand:
- Which assets depend on a specific part.
- How many equipment units could be affected by a shortage.
- Whether a spare is shared across multiple assets.
- Which components are important for critical equipment.
- Where stocking levels need closer review.
This can lead to both shortages and excess inventory. The company may hold too many low-priority parts while missing a component that could stop a critical asset.
Build the Asset-BOM Structure Around Equipment, Not Just Part Numbers
Fixing missing relationships does not require every organization to map every asset at once. A practical approach is to start with equipment where the impact of a spare-part problem is highest.
Start With the Assets That Matter Most
Prioritize assets such as:
- Production bottleneck equipment.
- Safety-critical assets.
- Equipment with frequent failures.
- Machines with long supplier lead times.
- Assets with high repair costs.
- Equipment that is difficult to source or replace.
This allows the company to build a useful BOM structure in stages.
For example, a manufacturer may begin with its main production line, compressors, pumps, and critical electrical systems. Once these records are validated, the organization can expand the structure to other equipment.
Create a Consistent Component Structure
A practical asset hierarchy can follow this pattern:
Site → Asset → Assembly → Component → Spare Part
Each level should help users understand where a part belongs and how it relates to the equipment.
Relevant information may include:
| Information | Purpose |
| Asset ID and equipment model | Identifies the equipment |
| Assembly or component name | Shows where the part fits |
| Manufacturer part number | Helps confirm the correct specification |
| Internal stock code | Connects the part to inventory |
| Quantity required | Shows how many units the asset needs |
| Approved alternatives | Identifies acceptable substitute parts |
| Revision or compatibility notes | Records model or configuration limits |
| Criticality details | Supports maintenance and stock decisions |
The BOM should reflect the equipment’s actual installed configuration—not only the manufacturer’s original parts catalog.
A machine may have been modified after installation. Components may have been replaced with updated versions, or an approved alternative may have been introduced. If these changes are not reflected in the BOM, the information can become unreliable.
Validate the BOM Before Using It for Planning
Before using a BOM for maintenance planning or purchasing, companies should check its accuracy.
Useful validation sources include:
- Equipment manuals and technical drawings.
- Manufacturer nameplates and part catalogs.
- Supplier documentation.
- Physical equipment inspections.
- Existing maintenance records.
- Input from experienced technicians.
Validation is especially important for components with similar names or specifications. A small difference in size, material, voltage, rating, or revision may affect compatibility.
Substitutions and equipment modifications should also be reviewed. A part that was suitable for an earlier configuration may no longer be correct.
Keep Asset-BOM Relationships Connected to Everyday Maintenance
An asset BOM should not remain a static spreadsheet that is reviewed only during an audit. It should support the daily activities of maintenance, procurement, and inventory teams.
A computerized maintenance management system (CMMS) can help connect asset records, BOM structures, inventory details, and work orders. The specific workflow depends on the system and its configuration.
When these records are connected, teams can use asset and component information during routine maintenance activities.
For example, BOM data may support:
- Preventive maintenance job plans
- Work order parts requirements
- Spare-part reservation and issue
- Reorder planning and purchasing
- Equipment repair history
- Spare-part criticality reviews
Platforms such as TeroTAM help organizations centralize asset and maintenance information. Companies can assess how their asset records, inventory data, and maintenance workflows can be organized to improve spare-part visibility.
Track Whether the Relationships Are Working
The number of BOM records created does not show whether the organization has improved its maintenance readiness.
Instead, companies should measure whether accurate asset-part relationships are reducing operational problems.
Useful measures include:
- Percentage of priority assets with validated BOMs.
- Work orders were delayed because of missing or incorrect parts.
- Incorrect spare-part issues.
- Emergency purchases.
- Inventory corrections related to part identification.
- Time required to identify the correct component.
These measures can help identify gaps and show whether the BOM structure is supporting maintenance teams.
The goal is not simply to create more records. It is to make sure that the right spare part can be identified, sourced, and issued when equipment needs it.
Summing it up
Missing asset-BOM relationships create more than a data management problem. They can affect maintenance planning, purchasing accuracy, inventory control, and equipment availability.
A reliable asset BOM connects equipment to the components required to maintain it. When companies build these relationships, validate them against actual equipment configurations, and keep them connected to daily maintenance work, they can reduce avoidable spare-part delays.
Want to improve how your organization manages asset and maintenance information? Contact TeroTAM at contact@terotam.com to discuss your maintenance management requirements.
