A maintenance technician needs a sensor. The part is already on the shelf, but its description is incomplete and its manufacturer part number sits inside a free-text field. A search misses it, so another purchase follows.

The immediate problem looks like availability. Underneath it sits a chain of decisions about material data, stock levels and purchasing.

Improving spare parts management means addressing that chain in the right order. Teams need to understand what they hold, decide what they need and establish processes that keep both the data and the inventory under control.

SPARROW’s experience analysing more than 200 plants and over €600 million of spare parts stock informs a roadmap for doing exactly that.[1]

Why spare parts problems keep returning

An incomplete material record affects much more than search. If teams cannot reliably identify a part, they struggle to recognise duplicates, compare suppliers or see whether another site already holds it.

The same physical item can appear under several descriptions. For example, a sensor recorded as “SME-8MZS24V” may be difficult to recognise as the same item recorded as “SME-8M-ZS-24V Festo”. Different records can then lead to separate orders and stock that nobody realises is duplicated.

Our findings show that the median share of records without a manufacturer part number in a dedicated field was 62%. The number was either missing or buried in the description. In our analysis, the median share of descriptions containing only a basic name, or less useful information, was 30%.[1]

These gaps help explain why a warehouse can hold substantial stock while maintenance teams still struggle to find what they need. When a part can’t be found, people buy around the catalogue. 

Inventory decisions introduce another difficulty. A part with no recent consumption may be surplus, or it may be an essential insurance spare for equipment whose failure would stop production. Movement history alone cannot tell the difference.

Criticality and supplier lead time provide the context needed to make that distinction. Without them, reducing inventory becomes difficult to justify, and keeping everything becomes the safer default.

Four questions that define the roadmap

Spare parts excellence depends on four connected areas:

• Find: Can teams identify the part and see what already exists in the system?
• Stock: Do you hold the right parts in the right quantities, with equipment criticality informing the decision?
• Buy: Can you source the part in time, through the appropriate supplier and purchasing process?
• Sustain: Do everyday processes keep records and planning parameters current?

Each area can sit at a different level of maturity. A plant may have well-structured material data but outdated stock settings. Another may manage critical spares carefully while buying frequently through free-text purchase orders.

The roadmap helps teams identify those gaps and decide what to address first. We do this using four levels of spare parts management: 

• Typical - habit decides 
• Visible - data shows the problems: gaps, duplicates and excess are measured and valued
• Controlled - rules decide: one clean record per part, with criticality and demand setting stock levels
• Excellent - changes in usage and supply trigger action. 

A plant can be Controlled on Find and still Typical on Buy, so the roadmap is about identifying those gaps and deciding which to close first.

Step 1: From typical to visible

At the first stage, everyday habits drive many decisions. Teams reorder familiar quantities, copy planning parameters or buy outside the material catalogue when searching takes too long.

The first task is to establish a baseline using existing ERP data.

That means examining the material master alongside stock, goods movements and purchasing records. The aim is to identify where incomplete data, supply risks and excess inventory affect operations, and attach a value to the problems where possible.

Six measures provide a useful starting point:

1. The share of materials with a manufacturer part number in a dedicated field.
2. The share of materials with criticality maintained.
3. The stock value with no goods movement in the previous 24 months.
4. The share of materials with meaningful lead times rather than blanket defaults.
5. Purchasing spend on order lines without a material number.
6. The share of stocked materials whose planning parameters have not been reviewed in the previous 18 months.

These measures support different decisions. Idle stock needs investigation before anyone labels it excess. A common default lead time needs checking against supplier performance. Free-text purchasing can reveal items that teams repeatedly buy but cannot easily find in the catalogue.

A baseline also helps focus the work. Instead of asking every plant to clean every record at once, teams can prioritise the gaps with the greatest financial or operational impact.

Step 2: From visible to controlled

Once the problems are visible, teams need clear rules for correcting them and preventing their return.

Start with identification. Extract manufacturer part numbers from descriptions, standardise records and review duplicates so that teams can recognise the same physical item consistently. Consolidation should preserve the stock and purchasing information needed for daily operations.

Then improve the information behind stock decisions. Maintain criticality, supplier lead times and vendor information, and use that context alongside consumption to set replenishment parameters.

This can lead to different actions for different parts. An overstocked item may need a pause in purchasing while existing stock is used. A critical component with a long lead time may need stronger coverage. Both decisions can form part of the same optimisation programme.

Purchasing processes need attention too. Recurring free-text purchases should prompt a review of whether the item belongs in the material catalogue. Before creating a new record, teams should search and check for an existing match.

Assigning ownership matters here. Someone needs responsibility for approving material creation, resolving unclear records and maintaining the rules. Otherwise, each clean-up risks becoming the starting point for the next one.

Step 3: From controlled to excellent

At a more advanced stage, changes in equipment, usage or supply trigger a review or update of the relevant decisions.

A supplier’s lead time increases. A component becomes obsolete. Equipment is retired. Consumption changes. Each development may affect what should be held, where it should be held or how it should be sourced.

Linking material records to equipment and usage helps teams assess those changes. Visibility across plants also allows them to check whether an available part can be transferred before placing another order, subject to local requirements and agreed pooling rules.

Automation can support this process by identifying changes and prompting action. Its value depends on reliable records and clear decision rules, including protection for critical insurance spares whose low consumption is intentional.

This is how improvements become part of daily operations. Teams keep the data and planning settings current as circumstances change.This step does not end. Around 5% of a catalogue is created new every year, so without it the problems come back.

A business case that separates inventory release from recurring savings

A credible business case should distinguish between reducing existing stock and improving future purchasing.

Inventory release happens as teams consume or redistribute surplus stock and avoid replenishing it unnecessarily. The benefit develops over time and depends on what can actually be used or transferred.

Recurring purchasing savings come from ongoing improvements such as preventing duplicate orders, sourcing through appropriate catalogue items and keeping replenishment decisions aligned with operational needs.

Treating these benefits separately helps teams explain when value should emerge and avoid counting the same avoided purchase twice. Operational measures, including part availability and search effort, help assess whether the changes are improving daily work.

Your roadmap starts with your own data

The first step is to establish where you stand today.

Which parts are difficult to identify? Which stock levels lack a clear rationale? Where do purchasing processes bypass the catalogue? And which decisions have remained unchanged while operating conditions have moved on?

The SPARROW MRO Value Scan uses your existing ERP data to uncover those gaps, assess optimisation potential and help prioritise the work.

Request an MRO Value Scan to build a roadmap based on your own spare parts data.

[1] Source: SPARROW internal analysis