Materials Classification, Codification and Standardization

Introduction

Materials management depends on the ability to identify, describe, locate and control every item held or purchased by an organization. In a store, an item may be known by a trade name, a local nickname, a supplier’s part number, a drawing number or a vague description such as “bolt” or “bearing.” Such variation causes duplicate purchasing, incorrect issues, excess inventory, delays and unreliable records.

Materials classification, codification, cataloguing, specification and standardization provide the information foundation for stores and warehouse management. They convert unstructured descriptions into a logical and controlled materials information system. The objective is not merely to assign numbers. It is to create a common language linking engineering, purchasing, stores, production, maintenance, finance, quality and suppliers.

A sound system should make it possible to answer five questions quickly:

1. What is the item?
2. How is it different from similar items?
3. Where is it stored?
4. How much is available or required?
5. Can an existing standard item be used instead of purchasing a new variety?

Learning Objectives

After studying this chapter, the learner should be able to:

• explain the meaning and purpose of materials classification and codification;
• distinguish classification, identification, codification, cataloguing and specification;
• design a practical material code and item master record;
• write complete and unambiguous material descriptions;
• apply standardization, simplification and variety-reduction principles;
• identify weaknesses in coding systems and propose controls;
• use digital tools and governance practices to improve material-data accuracy.

1. Basic Concepts and Terminology

Materials identification

Materials identification is the process of determining the exact identity and characteristics of an item. Identification must distinguish one item from all others that could reasonably be confused with it. A description such as “washer” is insufficient; “Washer, flat, carbon steel, M12, ISO 7089, zinc plated” is substantially more useful.

Classification

Classification is the grouping of materials according to common properties, use, form, source or other logical criteria. Examples include raw materials, components, consumables, spare parts, packaging materials and capital equipment. Classification answers the question: To which family does this item belong?

Codification

Codification is the systematic assignment of a unique symbol, number or alphanumeric code to an item. A code may be significant, in which its characters convey meaning, or non-significant, in which the code is simply a unique identifier.

Catalogue and item master

A catalogue is an organized list of materials containing descriptions, codes, specifications and related information. In an enterprise resource planning system, the item master is the controlled database record for each material. A catalogue may be printed or electronic; an item master is generally transactional and connected to purchasing, inventory and accounting processes.

Specification

A specification states the technical, physical, chemical, functional and quality requirements an item must meet. It may refer to dimensions, grade, tolerance, performance, material, finish, test requirements, standards and packaging.

Standardization

Standardization is the adoption of agreed specifications, dimensions, grades, processes or methods. It promotes interchangeability, predictable quality and reduced variety.

Simplification and variety reduction

Simplification means removing unnecessary complexity from products, processes or material requirements. Variety reduction means reducing the number of different items used while retaining required performance. Standardization is the basis; simplification and variety reduction are managerial applications of that basis.

2. Why Classification and Codification Matter

Poor material identification produces several forms of waste:

• duplicate item records for identical materials;
• procurement of unsuitable or incompatible substitutes;
• excess stock caused by fragmented demand;
• stockouts because available stock is hidden under another description;
• inaccurate inventory valuation and consumption analysis;
• increased search time and picking errors;
• difficulty in warranty, recall and regulatory traceability.

A good system creates a single source of truth. It supports purchasing by enabling clear requests and supplier comparison. It supports stores by improving bin labeling, location control and issuing accuracy. It supports maintenance by linking spare parts to equipment and bills of material. It supports finance by improving valuation and expenditure classification.

The benefits are greatest when coding is combined with disciplined descriptions and approval procedures. A code alone cannot correct an incomplete or inaccurate specification.

3. Principles of an Effective System

An effective classification and codification system should follow these principles:

Uniqueness. One active code should represent one distinct item definition. The same item should not receive several active codes without a documented reason.

Exhaustiveness. The system should accommodate all present materials and likely future categories.

Flexibility. New items and technologies should be added without redesigning the entire code structure.

Simplicity. Codes should be short enough to enter and communicate accurately.

Uniformity. Similar attributes should appear in the same sequence and use the same units and abbreviations.

Non-ambiguity. A description should not depend on local slang, supplier brand names or unexplained abbreviations.

Interchangeability. Where technically justified, equivalent items should be linked so that authorized substitutes can be identified.

Security and governance. Changes to item definitions should be authorized, auditable and protected from uncontrolled editing.

Compatibility. The system should work with ERP, warehouse-management, purchasing and barcode technologies.

4. Classification Structures

Classification may use one criterion or a hierarchy of criteria. A practical hierarchy is:

1. Major class: raw material, spare, consumable, finished product, packaging or service item.
2. Family: fasteners, electrical components, lubricants, bearings, instruments or pipes.
3. Subfamily: hexagonal bolts, ball bearings, hydraulic oils or copper cables.
4. Specific item: the fully specified item with its unique characteristics.

Classification criteria commonly include:

Classification should not be confused with location. A bearing may be classified as a mechanical spare, while its current storage location may change. Similarly, classification should not be based solely on where an item happens to be stored.

ABC and other inventory classifications

Inventory-control classifications such as ABC, FSN and criticality are related but different from item identification. ABC classification normally ranks items by annual consumption value, while FSN groups items by movement frequency: fast-moving, slow-moving and non-moving. Criticality considers the consequence of unavailability. These methods may be applied after unique identification has been established.

For annual consumption value:

The result is expressed in currency per year. The method assumes that historical consumption and unit cost are sufficiently representative for the control period. It ranks inventory importance; it does not define the technical identity of an item.

5. Coding Systems

Significant and non-significant codes

A significant code conveys information. For example, a code might contain characters for material family, material type and size. Its advantage is recognition; its weakness is that changes in classification or attributes may make the code obsolete or misleading.

A non-significant code, such as a sequential number, carries no embedded meaning. Its advantage is flexibility and lower risk of incorrect interpretation. Its weakness is that users need the catalogue or system to understand the item.

Many modern organizations use a non-significant item number combined with a structured description and searchable attributes. This approach separates identity from changing technical information.

Example of a hierarchical code

Consider the code ME-BR-00125, where:

• ME = mechanical item;
• BR = bearing family;
• 00125 = sequential identifier.

This code identifies the record, but the technical description must still state the bearing type, dimensions, clearance, seal arrangement, load rating and applicable standard. The code should not be interpreted as proof of those properties unless the organization has formally defined that meaning.

Code design choices

Before selecting a code format, an organization should decide:

• maximum length;
• permitted characters;
• whether spaces, hyphens and leading zeros are allowed;
• treatment of obsolete and duplicate records;
• whether manufacturer part numbers are stored as references rather than internal identities;
• how revisions, batches, lots and serial numbers are handled;
• whether one code represents an item, a batch, a serial unit or a service.

A material code normally identifies an item definition. Batch and serial numbers identify particular instances or production lots and should not be confused with the item code.

6. Description and Specification Writing

A strong description uses a consistent attribute sequence. For example:

NUT, HEXAGONAL, M12, CARBON STEEL, PROPERTY CLASS 8, ISO 4032, ZINC PLATED

The sequence begins with the noun, followed by distinguishing attributes. Descriptions should avoid unnecessary commercial language and should use controlled abbreviations.

A useful description template is:

Noun – type/design – principal size – material/grade – performance or class – standard – finish – packaging or other essential attribute.

The exact sequence should be adapted to the material family. For electrical cable, conductor material, cross-sectional area, insulation, voltage rating and length may be more important. For lubricants, viscosity grade, performance classification, container size and manufacturer approval may be essential.

A specification should distinguish:

• mandatory requirements;
• acceptable tolerances;
• inspection and testing requirements;
• approved standards;
• acceptable alternatives;
• documentation required from the supplier.

The principle of description by attributes rather than brand alone is important. A brand may be included as an approved reference when compatibility or warranty requires it, but “Brand X equivalent” is not a complete technical specification.

Units and nomenclature

Use one controlled unit system, normally SI units where appropriate. Do not alternate between millimetres and inches without stating the unit. Record dimensions with consistent precision. “10 mm” and “10.0 mm” may imply different measurement precision in a controlled specification. Abbreviations such as “SS,” “MS” or “std” should be defined or avoided because they can have multiple meanings.

7. Cataloguing and the Item Master

A robust item master may contain the following fields:

The unit of measure requires special attention. A material purchased by a roll but issued by metre needs a defined conversion and a clear basis for inventory accounting. If one box contains 100 pieces, the organization must specify whether the stock unit is “piece” or “box.” Uncontrolled conversions lead to apparent quantity errors.

New-item creation process

A practical workflow is:

1. User submits a material request with technical and operational justification.
2. The catalogue team searches for existing or equivalent records.
3. Technical personnel validate the specification.
4. Stores and purchasing confirm unit of measure, storage and sourcing information.
5. An authorized master-data owner assigns or confirms the code.
6. The record is approved, published and linked to relevant bills of material or equipment.
7. Duplicate, obsolete or superseded records are blocked according to policy.

The search-before-create step is one of the most effective controls against duplication.

8. Standardization, Simplification and Variety Reduction

Standardization may be applied at several levels:

• design standardization: common dimensions and components;
• material standardization: approved grades and compositions;
• process standardization: common methods and inspection procedures;
• documentation standardization: common descriptions, units and forms;
• supplier standardization: controlled approved sources where justified.

Variety reduction should be evidence-based. Replacing ten types of lubricant with one is not automatically beneficial if equipment manufacturers require different formulations. A proposed reduction should consider technical compatibility, safety, warranty, legal requirements, availability, total cost and operational risk.

A simple variety-reduction review can follow these steps:

1. Extract item records by family.
2. Normalize descriptions and units.
3. Identify apparent duplicates and near-duplicates.
4. Consult engineering, maintenance, quality, purchasing and users.
5. Test interchangeability and performance requirements.
6. Select preferred standards and approved substitutes.
7. consume existing stock where safe and economical.
8. Block unnecessary new variants and monitor compliance.

The distinction between duplicate and similar is crucial. Two records are duplicates when they represent the same approved item. Similar items may differ in a technically important attribute such as pressure rating, temperature range, tolerance or chemical compatibility.

9. Worked Example: Detecting a Duplicate

A company has the following records:

The first two records describe the same item if the organization confirms that “grade 8.8” and “property class 8.8” are equivalent and that the coating requirement is the same. They should be merged or one should be made obsolete after checking open orders, stock balances and historical transactions.

The third record is not a duplicate because property class 10.9 is a different strength requirement. It may be a technically superior item, but it is not automatically an acceptable substitute. Engineering approval is required before substitution.

This example shows why text similarity alone is insufficient. Duplicate detection should combine normalized attributes, standards, units and technical review.

10. Applied Case: Industrial Maintenance Catalogue

Background

An illustrative manufacturing plant operates several production lines. Its maintenance store contains approximately 12,000 records. Different departments create records independently, using supplier names, abbreviations and handwritten descriptions.

Problem

A search for a common motor bearing produced six records. Stock appeared unavailable under one description even though usable bearings were held under another. Purchasers also bought incompatible seals because the catalogue did not record temperature and shaft-size requirements.

Analysis

A cross-functional team sampled mechanical spares and found three main causes:

• no mandatory attribute template;
• no duplicate search before new-item creation;
• inconsistent units and manufacturer references.

The team also discovered that location codes had been embedded in some item numbers. When stock was relocated, the code became misleading.

Approach and solution

The plant adopted a non-significant sequential item number for new records, retained manufacturer numbers as reference fields, and developed family-specific templates. Bearing records required bearing type, bore, outside diameter, width, clearance, seal arrangement and standard. Seal records required material, shaft diameter, housing diameter, temperature range and pressure limit.

A catalogue committee reviewed duplicate candidates. Engineering approved functional equivalence; stores verified physical stock; purchasing checked open orders; finance confirmed valuation treatment. Obsolete records were blocked rather than deleted so that historical transactions remained auditable.

Barcode labels were introduced after the data cleanup, not before it. A barcode accelerates reading, but it does not repair wrong master data.

Outcome

The plant reduced duplicate active records, improved search success and consolidated demand for selected standard bearings. Picking errors declined because bin labels and item descriptions matched. The plant retained separate records for bearings that looked similar but had different clearance or sealing requirements.

Learning points

1. Data governance must precede automation.
2. Technical equivalence requires competent approval.
3. Location, item identity and serial traceability are separate data concepts.
4. Variety reduction should preserve safety and equipment performance.
5. Historical records should be controlled, not casually erased.

11. Technology, Governance and Contemporary Practice

ERP and warehouse-management systems can enforce mandatory fields, search by attributes, control approvals and connect item records to purchasing and inventory transactions. Barcode and RFID technologies improve identification at receiving, put-away, picking and issuing stages. Optical character recognition and natural-language tools can assist in extracting attributes from old catalogues, but human validation remains necessary because abbreviations, OCR errors and conflicting specifications are common.

AI-supported duplicate detection can rank likely matches using descriptions, manufacturer references and technical attributes. It should be treated as decision support, not as an autonomous authority. The risks include false merges, exposure of confidential supplier information, biased recommendations and propagation of incorrect historical data.

Governance should define:

• data ownership and approval authority;
• naming and abbreviation standards;
• change-control and revision rules;
• treatment of obsolete and superseded items;
• audit trails and access permissions;
• periodic data-quality measures;
• retention requirements for safety and regulatory records.

Useful measures include duplicate rate, percentage of records with complete mandatory attributes, search success rate, wrong-item issue rate and time required to create an approved item. Measures should be interpreted carefully: a low number of new records may indicate successful standardization or may indicate that users are bypassing the formal process.

12. Challenges and Limitations

No classification system can eliminate all judgment. Some materials have multiple legitimate uses, changing specifications or project-specific requirements. Overly detailed codes become difficult to maintain; overly broad codes conceal important differences. Significant codes become misleading when their embedded attributes change. Non-significant codes require reliable search and catalogue discipline.

Standardization may conflict with innovation, local availability or equipment warranties. A single preferred item may create supply risk if it depends on one supplier. Variety reduction can also create operational risk when rare but critical spares are removed without considering failure consequences.

The solution is controlled flexibility: define standards, document exceptions, assess risk and review the system periodically.

Best-Practice Checklist

• Establish one approved item-master owner.
• Search the catalogue before creating a new record.
• Use family-specific description templates.
• Separate item codes from locations, batches and serial numbers.
• Record technical attributes, units and standards explicitly.
• Control synonyms, abbreviations and manufacturer references.
• Require technical approval for substitutions and mergers.
• Block obsolete records rather than deleting audit history.
• Review duplicates and near-duplicates periodically.
• Use barcodes, RFID or AI only after data quality is controlled.
• Link critical spares to equipment, bills of material and maintenance plans.

Chapter Summary

Materials classification groups items into logical families, while codification assigns unique identities. Cataloguing and item-master management convert those identities into usable records containing descriptions, specifications, units, storage data, procurement references and governance information. Significant codes may communicate meaning, whereas non-significant codes provide flexibility; in either case, the description and specification must be accurate.

Standardization establishes common requirements and dimensions. Simplification removes unnecessary complexity, and variety reduction decreases the number of items without compromising safety, quality or performance. Effective systems use consistent attributes, controlled units, duplicate searches, technical approval and auditable change management. Digital technologies can improve searching and transaction accuracy, but they cannot replace sound data governance or professional judgment.

Key Terms

Classification: Grouping materials according to common characteristics or use.

Codification: Assignment of a unique code or identifier to a material.

Catalogue: Organized list of material records and specifications.

Item master: Controlled database record used in enterprise transactions.

Specification: Statement of technical, quality and performance requirements.

Standardization: Adoption of common approved requirements or dimensions.

Simplification: Reduction of unnecessary complexity.

Variety reduction: Decrease in the number of material variants used.

Significant code: Code whose characters convey defined meaning.

Non-significant code: Identifier whose characters do not inherently describe the item.

Attribute: A characteristic used to describe or distinguish an item.

Interchangeability: Ability of one item to replace another without unacceptable loss of performance.

Unit of measure: Basis in which quantity is purchased, stored or issued.

Duplicate record: Separate record representing the same approved item.

Criticality: Consequence of material unavailability or failure.

ABC classification: Ranking based commonly on annual consumption value.

FSN classification: Grouping by movement frequency as fast, slow or non-moving.

Traceability: Ability to follow an item, batch or serial unit through records and use.

Master-data governance: Policies and controls for creating, changing and protecting core records.

Review Questions

Short Answer Questions

1. Define materials classification and state one practical purpose.
2. Distinguish a significant code from a non-significant code.
3. Why should location codes not be embedded in item identity codes?
4. List four attributes that may be required in a bearing specification.
5. What is meant by variety reduction?

Long Answer Questions

1. Explain the principles of an effective materials classification and codification system.
2. Describe a controlled workflow for creating a new item-master record.
3. Discuss the relationship among standardization, simplification and variety reduction.
4. Explain how poor descriptions and inconsistent units affect stores and purchasing performance.
5. Evaluate the advantages and limitations of significant and non-significant coding systems.

Analytical / Application Questions

1. A store has records for “oil hydraulic 68,” “hydraulic oil ISO VG 68” and “oil, hydraulic, 68 cSt.” Design an investigation process to determine whether they are duplicates or different items.
2. A maintenance department proposes replacing eight types of seals with one standard seal. Identify the technical, commercial and safety checks required before approval.
3. Design a minimum item-master data set for a critical electrical spare and justify each field.

Multiple Choice Questions with Answers

Question 1

Which statement best describes codification?

A. Grouping items according to their storage locations

B. Assigning a unique identifier to a material

C. Calculating annual inventory consumption

D. Selecting a supplier for a material

Correct Answer: B. Assigning a unique identifier to a material

Question 2

Which description is most complete for a fastener?

A. Bolt

B. Steel bolt

C. M12 bolt

D. Bolt, hexagonal, M12 × 50, property class 8.8, ISO 4017, zinc plated

Correct Answer: D. Bolt, hexagonal, M12 × 50, property class 8.8, ISO 4017, zinc plated

Question 3

What is the main weakness of a significant code?

A. It cannot be entered into a computer

B. It may become misleading when embedded attributes change

C. It cannot distinguish two materials

D. It always requires a supplier number

Correct Answer: B. It may become misleading when embedded attributes change

Question 4

Which activity should normally occur before creating a new item record?

A. Delete all obsolete transaction history

B. Change the warehouse layout

C. Search for an existing or equivalent record

D. Order the material immediately

Correct Answer: C. Search for an existing or equivalent record

Question 5

ABC inventory classification commonly ranks items according to which measure?

A. Annual consumption value

B. Physical colour

C. Supplier distance

D. Number of storage bins

Correct Answer: A. Annual consumption value

Question 6

Two records describe identical bolts except that one specifies grade 8.8 and the other grade 10.9. How should they initially be treated?

A. Automatically merge them

B. Treat them as different until technical equivalence is approved

C. Delete the higher-grade record

D. Use the cheaper code for both

Correct Answer: B. Treat them as different until technical equivalence is approved

Question 7

Which data element identifies a particular production lot rather than the general item definition?

A. Item family

B. Unit of measure

C. Batch number

D. Commodity group

Correct Answer: C. Batch number

Question 8

What is the principal purpose of standardization?

A. To increase the number of material variants

B. To adopt agreed requirements and dimensions

C. To conceal technical differences

D. To eliminate all supplier competition

Correct Answer: B. To adopt agreed requirements and dimensions

Question 9

A company consumes 2,000 units of an item annually at a unit cost of $5. What is its annual consumption value?

A. $400

B. $2,000

C. $7,000

D. $10,000

Correct Answer: D. $10,000

Question 10

Why should barcode implementation generally follow catalogue cleanup?

A. Barcodes cannot be printed before cleanup

B. Barcodes accelerate identification but do not correct inaccurate master data

C. Barcodes are used only for financial records

D. Catalogue cleanup makes barcodes unnecessary

Correct Answer: B. Barcodes accelerate identification but do not correct inaccurate master data