Published: .
- The Myth of the Straight Line
- Three Scenarios That Break Linearity
- What Standards Say About Segmentation
- Four Consequences of "Linear" Thinking for Documentation
- Documentation Features for Industrial Software Developers
- Hidden Complexities Rarely Mentioned
- Comparison of Architectures: Monolith vs. Library
- When Modular Architecture Works
- Conclusion
A service engineer arrives to commission a new production line. In their hands is a 1200-page user manual. They search for the "Commissioning" section — and find it. But three hours later, it turns out that the controller settings are described in the "Maintenance" section, because the author decided to group everything related to electronics into a single chapter. The startup is delayed by a day. The manufacturer loses reputation. The customer loses money. All because of one document that tried to be everything to everyone.
This article explores the optimal user manual structure for machinery and why proper technical documentation for industrial equipment is not just a best practice but a compliance requirement.
Documentation segmentation by lifecycle phases is not an author's invention. It is directly or indirectly embedded in IEC/IEEE 82079-1, which defines IEC/IEEE 82079-1 requirements for information for use, including IEC 82079-1 lifecycle phases such as commissioning, operation, and decommissioning. Other key standards include ISO 20607:2019, IEC 61508, and industry standards such as API 18LCM and NORSOK Z-018. These documents require different approaches to describing commissioning, maintenance, and decommissioning — which means a single all-purpose manual no longer meets regulatory expectations.
The Myth of the Straight Line
Most manufacturers of technical equipment think of the lifecycle as a sequence: designed → manufactured → delivered → commissioned → operated and maintained → decommissioned. In this logic, one document covers everything: from unpacking to disposal. The logic seems reasonable, but it is flawed.
Reality is different. The customer's equipment does not exist in a vacuum — it is modernized, retrofitted to meet new standards, and brought into service in stages. These stages overlap, loop back, and run in parallel. A single document for everything is an attempt to describe a labyrinth as a corridor. It is doomed from the start.
This is where segmentation comes in — dividing documentation into independent modules, each covering a specific lifecycle phase and addressing a specific audience. This is exactly what modern standards require.
Three Scenarios That Break Linearity
The equipment lifecycle in reality is not a perfect straight line. Here are three scenarios that prove this.
1. The Modernization Loop
Equipment is not decommissioned as a whole. Often, only one component is replaced — a power supply or a control module. Or only the firmware is updated. What is this from a lifecycle perspective? It is simultaneously decommissioning the old component and commissioning the new one on a running system. The commissioning instructions assume work with new equipment on a new site — a "clean slate" with no old settings or neighboring working units. But in this situation, everything is different: you need to replace the component without stopping production, with minimal downtime. Where in your monolithic document is the section for this hybrid scenario? It does not exist.
2. Retrofit of Industrial Equipment
Retrofit is the modification of already operating equipment to meet new requirements. Five years after commissioning, a new industry standard is issued or safety requirements change. The equipment is not decommissioned, but it needs to be modified: add protective covers, change control algorithms, replace sensors. This is not maintenance — there is no breakdown. This is not new commissioning — the equipment is already running. This is "supervised operation," requiring temporary procedures, shutdown and restart protocols. The standard user manual does not have sections for this.
3. Cascaded Commissioning of Industrial Equipment
A large plant is not always started up all at once. First, one production line is started, then a second, then a third. The first line is already running and being maintained, the second is being installed, the third is in the adjustment phase. In one location, commissioning, operation, and maintenance happen simultaneously. The instructions conflict: installers work with one set of documents, operators with another, and these processes overlap.
These three scenarios are not exceptions — they are common practice for complex industrial equipment. And each of them makes a single monolithic document useless.
What Standards Say About Segmentation
The idea of dividing documentation by lifecycle phases is embedded in a number of regulatory documents. Let us look at the key ones.
IEC/IEEE 82079-1 — Information for Use
IEC/IEEE 82079-1 provides principles and general requirements for information for the use of products. It applies to phases of the product life cycle such as transport, assembly, installation, commissioning, operation, monitoring, troubleshooting, maintenance, repair, decommissioning, and disposal. For each of these phases, different information is required, intended for different categories of users — from skilled specialists to unskilled personnel.
This standard does not prescribe a single document. It requires that the information be structured according to the lifecycle phases and the tasks performed at each phase.
ISO 20607:2019 — Safety of Machinery — Instruction Handbook
ISO 20607:2019 specifies requirements for the machine manufacturer for the preparation of the safety-relevant parts of an instruction handbook for machinery. It applies taking into account all phases of the life cycle of the machine and provides further specifications to the general requirements on information for use given in ISO 12100.
Key requirements include:
- description of all potential hazards and risk areas;
- instructions for safe startup, operation, and shutdown of equipment;
- measures to prevent abnormal situations;
- rules for maintenance and repair.
This standard requires that information be structured and presented according to the different phases of the machine’s life cycle and the tasks performed. While it does not explicitly mandate physical separation into multiple files, logical segmentation is the most effective way to meet these clarity and usability requirements, especially for complex machinery.
IEC 61508 — Functional Safety
IEC 61508 is an international standard that establishes requirements for the lifecycle phases of safety-related systems. It defines an overall safety lifecycle that begins with concept development and hazard analysis and progresses through design, implementation, operation, and decommissioning. The standard includes phases such as:
- hazard and risk assessment;
- safety requirements specification;
- design and engineering of safety functions;
- validation and verification;
- operation, maintenance, and modification;
- decommissioning.
Modification and retrofit are addressed within the Operation and Maintenance phase and trigger a partial restart of the safety lifecycle (including risk reassessment). This supports scenario #2: while not always a top-level "phase" in the diagram, the standard strictly mandates that any modification be treated with the same rigor as initial design, requiring specific documentation and validation procedures distinct from routine maintenance.
EU Machinery Directive 2006/42/EC
Under the EU Machinery Directive 2006/42/EC, which sets EU Machinery Directive 2006/42/EC documentation obligations, each manufacturer is obliged to document the individual development phases of a plant or machine. The technical documentation must show which requirements of the Directive are applied and fulfilled and must be available for at least 10 years following the date of manufacture.
The Directive requires the manufacturer to provide an "Instruction Handbook" containing all necessary information for safe use. It does not prescribe a specific format (single vs. multiple documents). However, a well-segmented structure significantly reduces the risk of the documentation being deemed unclear or incomplete during conformity assessment, as it allows auditors to easily verify that all required safety information for each lifecycle phase is present and accessible.
API 18LCM — Product Lifecycle Management (Oil & Gas)
API 18LCM defines the requirements of a management system for service providers performing lifecycle management of products for organizations in the petroleum and natural gas industry. It covers the product from the time it is placed into the lifecycle management program until it is decommissioned and requires documented traceability, repair and maintenance history, and installation records.
This standard explicitly requires that all lifecycle phases be supported by appropriate technical documentation.
NORSOK Z-018 — Supplier's Documentation of Equipment
NORSOK Z-018 specifies lifecycle documentation such as: describing/evaluating a bid, engineering a plant, receiving, handling, preserving, installation and commissioning, start, operation, maintenance, decommissioning and removal, and verifying the delivery.
The standard does not require everything to be in one document. It requires that each phase have its own section or its own document. Segmentation here is the natural solution.
Each of these standards in one way or another requires segmentation — either through mandatory sections, through the separation of individual lifecycle phases, or through the requirement for separate procedures. A monolithic document cannot satisfy all these requirements simultaneously without losing quality and usability.
Four Consequences of "Linear" Thinking for Documentation
When a manufacturer tries to fit everything into one document, systemic problems arise. Here are the four most painful ones.
1. Loss of Relevance
While you are writing the chapter on decommissioning, the chapter on commissioning has already become outdated due to firmware updates or configuration changes. A monolithic document cannot be updated pointwise — any change requires reissuing the entire document. As a result, the documentation either is not updated at all or is updated with a huge delay.
2. Access Conflicts
The installer needs the "Commissioning" section. The operator needs "Operating Modes." The service engineer needs "Troubleshooting." The environmental specialist needs "Disposal." When all of this is in one document, everyone has to flip through hundreds of pages to find what they need. And worse — they might accidentally read information that does not relate to their task and make the wrong decision.
3. Bureaucratic Paralysis
Decommissioning requires approvals from departments that did not exist at the production stage. Environmental specialists, lawyers, occupational safety services. Their requirements and regulations are formed during operation, and it is impossible to include them in a document created years earlier.
4. Versioning Problems
If you release a software update for the control system, do you reissue the entire 1000-page document? That is expensive, time-consuming, and pointless. But if you have separate documents, you only update the one related to the software — and that is all.
These consequences are not theoretical. They directly affect the cost of equipment ownership, safety, and the manufacturer's reputation. Segmentation allows you to avoid each of these problems.
Architectural Solution: From Monolith to Library
If one monolithic document does not work, what does? The answer: a document library. Each document in this library is responsible for a specific lifecycle phase and addresses a specific audience.
Modularity Instead of Sequence
The commissioning document must be self-contained. The maintenance document must be too. The decommissioning document as well. The connection between them is made through cross-references to common data: diagrams, specifications, environmental parameters, which are placed in a separate reference document.
This is not about creating dozens of scattered files. A logical structure is needed: each document solves its own task and does not try to solve others'. This is the right segmentation.
Live Updates
When disposal requirements change, only the decommissioning document is updated. This does not affect the commissioning document. When a new software version is released, only the relevant section is updated. The savings in time and money are obvious.
Binding to System State
Instead of "Commissioning Instructions," it is more logical to write "Instructions for Transition from State A (stopped) to State B (running)." This logic works for initial startup, restart after an accident, and planned shutdown. The document describes not the chronology, but the logic of transition between states.
Documentation Features for Industrial Software Developers
For software developers, this story looks especially familiar. Your product lives in a cycle of continuous updates: CI/CD, quarterly releases, security patches.
Commissioning for you is database setup, integration with external systems, data migration. Maintenance is monitoring, updates, bug fixes. Decommissioning is data extraction, instance removal, licensing issues, and regulatory compliance (e.g., GDPR when deleting personal data).
A single "user manual" does not work. You need separate documents: an administration guide, a migration guide, an update guide, an uninstallation guide. And each of these documents lives its own life, updated at its own pace. This is the same segmentation, only applied to a software product.
You do not write one instruction for an entire Kubernetes cluster. You write Helm charts for deployment, runbooks for incidents, and data sheets for PVC (Persistent Volume Claim) removal. Why not treat "hardware" the same way?
Hidden Complexities Rarely Mentioned
Even when a manufacturer agrees with the idea of separate documentation, complexities arise in practice. Here is what to know in advance.
Search and Navigation
When there are several documents, the problem arises: how does the user find the right one? The solution is a single portal or index where all documents are collected and tagged with metadata: lifecycle phase, target audience, version, update date. Without this, the library turns into a dump.
Usage Analytics
In a monolithic document, you do not know which sections are read and which are skimmed. In a digital library, you can track which documents are accessed most often, at which stages questions arise, where users "get stuck." This is data for improving documentation — but it needs to be collected and analyzed.
Maintenance and Updates
Separate documentation requires discipline. If each document does not have an assigned responsible person, they will inevitably become outdated. Owners need to be appointed: who is responsible for the commissioning document, who for maintenance, who for decommissioning. And a regular review schedule needs to be set — for example, with each release or once a year.
Total Cost of Ownership
Yes, separate documentation requires more effort upfront. But these efforts pay off: fewer commissioning delays, fewer maintenance errors, fewer disposal fines. The total cost of ownership decreases. A monolithic document is cheaper to produce but more expensive to operate.
Hybrid Approaches to Segmentation
In practice, pure cases — only monolith or only library — are rare. More often, a hybrid is used: a basic user manual (general information, safety, general description) plus separate appendices or supplements for specific phases. This is a compromise that works for small projects, but for complex equipment it is insufficient.
Comparison of Architectures: Monolith vs. Library
To clearly show the differences, let us compare the two approaches to documentation organization by key parameters.
| Parameter | Monolithic Document | Module Library (Segmentation) |
|---|---|---|
| Relevance | Quickly becomes outdated, updates require reissuing the entire document | Updated pointwise, each module is independent |
| Access to information | Difficult search, different users have to skim through irrelevant content | Clear separation by roles and tasks, fast navigation |
| Development cost | Low at start (one document) | Higher at start (several documents), but pays off through maintenance savings |
| Safety and risks | High risk of errors due to confusion between sections | Risk reduction, each user works with relevant information |
| Regulatory compliance | Often fails to address disposal and environmental requirements | Allows inclusion of all necessary sections for decommissioning |
Which approach do you choose?
When Modular Architecture Works
Documentation segmentation is not a panacea. It has its limitations.
When it works:
- Complex equipment with a long service life (10+ years).
- Equipment that undergoes modernization or retrofit.
- Products operated in different countries with different disposal requirements.
- Situations where different phases are handled by different organizations (manufacturer, integrator, operating company).
When it does not work (or is excessive):
- Simple equipment with a short service life (consumer goods, consumables).
- Products that do not require special knowledge during decommissioning.
- Projects with tight budget constraints where additional documents cannot be funded.
In each case, the decision is made based on the complexity of the product and user needs. But if your product is complex and has a long service life — a single monolithic document does not work.
Conclusion
The equipment lifecycle is not a straight line. It is a labyrinth of loops, returns, and parallel processes. One document for everything is an attempt to describe a labyrinth as a corridor. It does not work, and the standards confirm this.
The solution is in documentation segmentation, the transition from a monolithic document to a library of modules. Each module solves its own task, addresses its own audience, and is updated at its own pace. Such a solution requires more effort upfront, but pays off through reduced downtime, fewer maintenance errors, and the absence of disposal fines.
The document should reflect not the chronology of the equipment's life, but the logic of decision-making at each intersection. Review your current "master manual." Split it into three or four independent parts. Your customers will thank you — because they do not live linearly. Do not make them read linearly.