Units of measurement represent one of the most sensitive—and, paradoxically, most neglected—elements within the material and service records of industrial companies. Although they occupy only one field within the ERP system, their influence permeates the entire operation: purchasing, inventory, planning, negotiation, pricing, and process automation.

When poorly defined, units of measurement become one of the main sources of data distortion, generating silent disruptions, hidden costs, and flawed decisions. When well-structured, they become a solid pillar of materials governance and a natural driver of efficiency.

This article explores in depth what units of measurement are, why they play a central role in master data management, and how CH | Astrein structures, corrects, and governs this component to ensure operational reliability throughout the supply chain.

What are Units of Measurement?

Units of measurement are the standardized way of expressing quantities of materials — such as kilogram (kg), meter (m), liter (L), unit (un), among others.

In theory, it's a simple field within the ERP system. In practice, it's one of the elements that generates the most discrepancies, rework, and inconsistencies, especially in companies with extensive legacy databases or decentralized registration processes.

And why does this happen?

Because the market offers materials in different presentations, packaging, and formats, while companies create their own internal standards—often disconnected from the supplier's logic.

This misalignment creates a perfect environment for errors and distortions, as we will see later.

Why Units of Measurement are Fundamental for those working in Purchasing, Supply Chain, and MDM (Master Data Management)

Units of measurement directly affect:

1. Purchases and negotiation

• They influence the comparison between suppliers.

• They change the unit price and the consumption history.

• They directly impact management reports used for decision-making.

When a company buys "1 liter" and registers it as "1 bottle," it loses historical reference and harms future negotiations.

2. Inventory and planning

• Inflated or underestimated quantities lead to stockouts or overstocking.

• Discrepancies affect inventory, tax records, and internal controls.

A unit of measurement error can turn a planned purchase into an operational disruption.

3. Master data cleansing and governance

• Inconsistent units prevent automation.

• They distort indicators in the areas of supply and maintenance.

• They hinder the full use of ERP and analytical tools.

In legacy systems, the inability to retroactively change units of measurement imposes an additional challenge: it is necessary to correct the registration, redefine processes, and guide the client on how to handle old items.

4. Automation and digital efficiency

RPA processes, approval workflows, and integrations depend on clear standards. When units of measurement are incorrect or inconsistent:

• algorithms are unable to compare volumes.

• Orders are generated in absurd quantities.

• and entire workflows cease to be automatable.

It's the kind of detail that can bring down an entire digital transformation project.

The Real Problem: When Packaging Becomes a Unit of Measurement

One of the most frequent errors identified in CH | Astrein projects is the confusion between packaging and unit of measurement .

It is common to find registrations where:

• "box",

• "bottle",

• "can",

• "package"

They were recorded as units of measurement.

This creates significant distortions because the packaging is not the unit of measurement — it should be described in the item description , not in the unit field.

For example:

The company buys lubricating oil , which can be purchased:

• in a 200 L drum,

• in a 5 L gallon,

• in a 1 L can,

• in a 1 L bottle.

The material is the same, but the presentation changes. The packaging changes:

• the unit price ,

• the item code (SKU) ,

• the consumption calculation ,

• Purchase history .

The solution structured by CH | Astrein is clear:

In this way, the company preserves accounting and operational accuracy, avoids distortions in reports, and allows for correct comparisons between suppliers and periods.

Common Mistakes That Lead to Million-Dollar Losses

Over decades of projects, CH | Astrein has collected real-life cases that illustrate how an incorrect unit of measurement can trigger serious consequences.

Error 1 — The classic example: 500 screws… that turned into 500 kilos.

A customer requested 500 screws . However, the material was sold by weight , and the registration information was incorrect.

Result: 500 kg of screws arrived at the warehouse.

The error went through:

• request,

• approval,

• buy,

• receipt,

…without anyone noticing. This happens because the unit of measurement distorts the ERP logic, but doesn't generate an automatic alert.

Error 2 — The mountain of toilet paper

A customer requested "packages" of toilet paper.

But there were two types of packages:

• 12 rolls ,

• 64 rolls .

Both are listed as a "package," with no distinction in the description.

The result was a purchase that was massively larger than the actual need — the company filled almost an entire block of storage space with just toilet paper.

Will the item be consumed? Yes. But was it a waste? Also yes.

And all this because the packaging and the unit of measurement were mixed up .

How CH | Astrein Corrects and Structures Units of Measurement with Precision

In CH | Astrein's projects, the treatment of units of measurement has its own dedicated chapter , as it defines the reliability of the entire materials base.

The approach follows three pillars:

1. Structured sanitation of the existing infrastructure

Since ERP systems do not allow retroactive changes to the unit of measurement, it is necessary to:

• identify items that can remain as they are,

• Identify items that need to be replaced.

• Create new code when necessary.

CH | Astrein advises the client on which items should be blocked and recreated with a new pattern.

This step eliminates structural errors that have accumulated over the years.

2. Governance and creation of new items (ongoing)

After the sanitation phase, the governance structure is designed:

• definition of standards,

• automatic validations,

• presentation rules,

• alignment with suppliers,

• Integration with internal ERP conversion tables.

From this point on, all new items are created correctly , preventing future inconsistencies.

3. Strict use of the PDM (Material Description Standard)

PDMs ensure that:

• Similar materials use the same unit of measurement .

• Exceptions should be applied only when justifiable.

• Descriptions should only include presentation when it changes the SKU.

• Pipes, sheets, profiles, and raw materials can be sourced from suppliers who sell by weight ( kg) or by the meter , according to formalized criteria.

This creates a consistent, standardized foundation that is ready for automation.

Structured Flexibility: When Different Units Can Coexist in the Same Family

A family of materials does not always require a single unit of measurement.

Examples from the transcript itself:

• Steel sheets can be purchased by the square meter or by the kilogram;

• Pipes can be supplied by the meter or by the kilogram.

Flexibility exists, but it is always intentional and always documented .

CH | Astrein establishes rules so that:

• The ERP system understands the conversion.

• Comparisons between suppliers will still be possible.

• and ensure that consumption analyses are not compromised.

Without this infrastructure, any internal conversion creates noise and prevents automation.

Why do poorly defined units of measurement hinder automation?

At the 4th Forum on Intelligence in Purchasing Processes, one point became clear:

Automation is impossible when units of measurement are not standardized.

Digital processes depend on consistency.

If one item is "1 bottle" and another is "1 L", how will the system:

• Compare prices?

• Consolidate purchases?

• How to calculate consumption?

• Feed the planning?

• Generate reports?

The ERP system then requires manual intervention — which defeats the purpose of automation.

Errors in Units of Measurement Are Not Operational — They Are Strategic

What the transcript reveals, in a compelling way, is that units of measurement:

• They affect negotiations worth millions.

• They change the board's KPIs.

• distort analyses,

• They create misguided purchases.

• They increase inventory costs.

• They prevent automation.

• They generate rework in various departments.

Therefore, the solution is never just "fixing a field." It's about rethinking processes , governance , the role of departments , and corporate standards .

It's a leadership decision, not an operational one.

How to Apply Best Practices for Units of Measurement in Your Company

CH | Astrein's practical experience demonstrates a clear set of best practices:

1. Never use packaging as a unit of measurement.

Box, package, bottle, can, gallon — all of these should be in the description , not the unit of measurement.

2. Create different codes for different presentations.

If the volume or packaging changes, the SKU changes.

3. Standardize units by family (PDM)

Equivalent materials should use the same unit — with clearly documented exceptions.

4. In legacy databases, recreate the item when necessary.

Forcing maintenance on the wrong unit perpetuates distortions.

5. Establish conversion rules before integrating with the ERP.

This prevents internal inconsistencies and facilitates automation.

6. Establish governance before registering new items.

Never wait for a problem to arise before setting the standard.

7. Educate requesters and buyers.

Most errors occur at the source: during the request and registration process.

Without training, any standard fails.

The Most Common Challenges When Dealing with Units of Measurement

• Internal resistance to change.

• Legacy databases with thousands of items that are impossible to change.

• Lack of clear documentation.

• Discrepancies between internal units and supplier units.

• ERPs with poorly configured conversion tables.

• Applicants who do not understand the financial impact.

• Buyers who analyze prices without considering presentation.

These challenges cannot be solved in isolation. They require a combined approach encompassing technology, process, and cultural change.

How CH | Astrein Supports Companies in Standardizing Units of Measurement

CH | Astrein is a global pioneer in technologies and methodologies for master data cleansing and governance. Its approach to units of measurement is recognized in the market for its precision and ability to completely reorganize material databases—even in critical scenarios.

The company supports its clients in:

• detailed analysis of the legacy,

• Correction and recreation of critical items.

• standardization by family,

• definition of presentation rules,

• alignment with suppliers,

• ongoing governance implementation,

• internal team training,

• Continuous monitoring of registration quality.

The result is a reliable foundation capable of supporting automation, strategic analysis, and robust decision-making.

Conclusion: Units of Measurement Are the Invisible Basis of Efficiency

Although they may seem like just one field within the ERP system, units of measurement underpin the entire operational logic of purchasing, inventory, planning, analysis, and automation.

When neglected, they lead to waste, incorrect purchases, and inconsistent data. When structured, they enable governance, reduce costs, and increase the organization's digital maturity.

Any company that wants to grow sustainably needs to look at units of measurement with the same rigor it applies to contracts, negotiations, and technology.

And this process requires method, depth, and practical experience — which CH | Astrein has mastered for decades.

Want to know how to improve your units of measurement?

CH | Astrein can accurately estimate the operational and financial impact of standardizing units of measurement on your company. Contact us and discover how to strengthen your purchasing, inventory, and master data governance efficiency.

Final Tip

All automation begins with a good unit of measurement. If the foundation isn't reliable, no digital project can stand.

FAQ — Frequently Asked Questions about Units of Measurement

1. Why do units of measurement have such a significant impact on the purchasing area?

Because they alter the unit price, consumption history, and the ability to compare suppliers. Without standardization, strategic decisions are compromised.

2. Can I change the unit of measure for an item already registered in the ERP system?

Generally not. In many ERP systems, making retroactive changes can lead to serious distortions. The recommended approach is to block the item and create a new one.

3. Can packaging be a unit of measurement?

No. Packaging should be in the description. The unit should represent the actual quantity.

4. How do I know if I need to recreate an item?

When the current unit distorts calculations, pricing, history, inventory, or automation, the analysis is performed during the cleanup phase.

5. Do all families need to have the same unity?

Most are possible, but some families—such as sheets and tubes—allow for multiple units, provided they are documented and governed.