You can’t manage spare parts you can’t see: Why inventory visibility is the real MRO bottleneck

In manufacturing, spare parts problems are often discussed as purchasing, supplier, or planning problems.

In reality, most of them start with a much simpler issue: lack of visibility.

Many manufacturers lack a clear view of which spare parts they actually have, where they are located, or how critical they are. Not within a single plant. And certainly not across an entire production network.

Everything starts with knowing what you have. Without that foundation, every downstream decision becomes reactive. Buying, stocking, and expediting turn into guesswork rather than strategy.

Industry data confirms that this is not an isolated observation. It is a systemic issue that explains why so many organizations are simultaneously overstocked and underprepared.

Most manufacturers are flying blind on spare parts inventory

In conversations with maintenance, procurement, and operations leaders at manufacturing enterprises, one theme keeps coming up: nobody fully trusts the inventory numbers.

Parts are listed in the ERP, but technicians still cannot find them. Other parts exist physically, but under different names or material numbers. Entire categories of spare parts are duplicated across sites without anyone realizing it.

This is one of the most common starting points I see on factory floors. Teams are doing their best with the information they have, but that information is fragmented, outdated, or incomplete.

Martin Weber
CEO | SPARETECH

The data support this reality. According to the MRO strategy gap report, 45% of manufacturing executives cite a lack of inventory visibility across sites as their top MRO challenge. This is higher than downtime, obsolete stock, or workforce constraints.

When visibility is missing, spare parts management becomes reactive by default. Teams buy externally because they cannot confidently reuse internally. They overstock locally because they cannot see globally.

The visibility paradox: excess inventory and stockouts at the same time

One of the clearest signs that visibility is broken is the paradox many manufacturers experience today.

On one hand, inventory levels continue to rise. On the other hand, critical spare parts are still missing when they are needed most.

The industry data makes this contradiction explicit:

• 32% of respondents report high capital tied up in excess stock
• 32% also report frequent stockouts of critical spare parts

These two problems should not coexist. If inventory volume alone reduced risk, stockouts should disappear. Instead, manufacturers are holding more spare parts than ever and still scrambling during breakdowns.

The reason is simple. Without transparency, inventory grows in the wrong places. Low criticality parts accumulate quietly, while truly important items remain unavailable or hard to locate.

In short, inventory quantity does not equate to inventory quality.

When visibility fails, workarounds take over

A lack of visibility does not stop work. It just changes how work gets done.

In one factory visit, Martin Weber describes, a multimillion-dollar operation was running its spare parts intake on a handwritten sheet of paper. Technicians wrote down part information by hand. A storeroom clerk tried to decipher it, searched the ERP, and either matched an existing part or created a new one.

In many plants, similar workarounds emerge as a practical response.

When people lack reliable information, they create workarounds to keep production moving. Excel sheets before the ERP. Local naming conventions. Duplicate material numbers created just to avoid delays.

The MRO strategy gap report shows how widespread this situation is. 22% of executives explicitly identify poor data quality as a major MRO challenge, but the real impact is much broader. Inconsistent and incomplete data sit underneath many higher-level problems, from overstocking to downtime.

These workarounds keep plants running in the short term, but they quietly lock in inefficiency. Every duplicate part, every local shortcut, makes network-level visibility harder over time.

What changes once spare parts become visible

The moment manufacturers gain clarity about what they have, a different set of decisions becomes possible.

Visibility is not the goal by itself. It is the enabler.

Once teams can actually see spare parts across sites, several things change immediately:

• Internal sourcing becomes a real option before external purchasing
• Parts can be reused or transferred instead of reordered
• Criticality can be assessed based on real downtime impact, not assumptions
• Supplier searches become faster and more targeted

These improvements are not driven by aggressive cost-cutting. They are driven by fewer blind decisions.

Visibility is a prerequisite for standardization and scale

As organizations grow, the cost of poor visibility increases exponentially.

Only 8% of manufacturers describe their spare parts management as fully standardized. Most remain partially standardized, meaning that some sites follow shared rules while others operate independently.

Without visibility, standardization becomes nearly impossible. You cannot harmonize what you cannot compare. You cannot govern what you cannot see.

This is why visibility problems tend to worsen at scale. Each plant adds its own spare parts logic, safety buffers, and naming conventions. Over time, the organization ends up with thousands of spare parts that look different on paper but are identical in reality.

The result is higher inventory levels, slower response times, reduced decision confidence, and increasing coordination effort between maintenance and procurement teams.

From reactive buying to operational confidence

At its core, visibility-driven spare parts management strengthens decision confidence.

When teams trust their data, they stop compensating with excess inventory. When they can see across sites, they stop buying defensively. When they understand criticality, they stop treating all spare parts as equally urgent.

Martin Weber often frames this shift as moving from reactive protection to operational confidence. Instead of buying spare parts to avoid blame, organizations build systems that allow them to explain and justify their decisions.

That confidence does more to protect uptime than additional stock ever could.

What to do next

Manufacturers looking to improve spare parts performance should start with a simple diagnostic:

• Can we see spare parts availability across sites, or only locally?
• How often do we buy parts we already own elsewhere?
• How much of our inventory is visible only on paper, not in practice?
• Where are workarounds compensating for missing information?

These questions often reveal structural visibility gaps rather than pure purchasing issues.

Before reducing inventory or renegotiating suppliers, focus on making spare parts visible. Once teams can clearly see what they have, better decisions follow naturally.