Project Documentation & Analysis Service
Understanding what your PLC code actually does shouldn’t require the original programmer.
I provide comprehensive documentation and analysis services for CODESYS and TIA Portal projects, transforming undocumented or poorly documented code into clear, structured technical documentation that your team can actually use.
Whether you’re inheriting a legacy system, need proper handover documentation, or want to understand the logic behind critical industrial processes, I deliver professional documentation that bridges the gap between the code and the people who need to maintain it.
What This Service Covers
Complete Code Walkthrough
A structured explanation of what the PLC project is doing and how it is organised.
- Program blocks, functions, and data structures explained
- Execution flow, sequencing, and task behaviour mapped out
- Functional areas broken down into understandable sections
I/O and Configuration Reference
Clear documentation for the physical and configured parts of the system that people usually end up tracing manually.
- Inputs and outputs catalogued with purpose and usage
- Hardware, network, and communication settings documented
- Useful as a maintenance reference and handover asset
Critical Analysis
More than description. I call out the areas that are confusing, fragile, risky, or likely to cause trouble later.
- Complex logic and hidden assumptions highlighted
- Maintainability issues and problem areas identified
- Potential errors and technical debt clearly flagged
Modification and Handover Support
Documentation that helps you plan changes safely and gives your team something practical to work from afterwards.
- Useful for upgrades, contractor handover, and system audits
- Guidance on integration points for future changes
- Editable deliverables your team can keep using internally
My Approach
I read and analyze your PLC code directly, understanding what’s happening with minimal supporting context. While knowing what the system controls is helpful, I can work effectively even without detailed background information – the code tells its own story when you know how to read it.
This means you don’t need to spend hours briefing me or digging up old commissioning documents. Send me your project files, give me a brief overview of what the system does, and I’ll take it from there.
Supported Development Environments
I work with the following PLC programming environments:
- SIMATIC Manager
- TIA Portal V15, V16, V17, V18, V19, V20
- CODESYS 2.3
- CODESYS 3.5
Other environments can be worked with, however licensing requirements may increase costing or be a barrier to performing the task. If it’s possible to share resources (VM access, TeamViewer, remote desktop), this could resolve licensing constraints. I’m open to discussing options for your specific environment.
What You’ll Receive
I deliver a comprehensive Word or PDF document that becomes the definitive reference for your PLC project. This isn’t a superficial overview – it’s an in-depth analysis that covers everything your maintenance team, project engineers, or future programmers need to understand the system.
Comprehensive Program Walkthrough
A structured explanation of the main program blocks, function blocks, functions, data structures, and how they fit together.
Project Structure and Flow
Clear documentation of hierarchy, scan behaviour, execution order, and the main functional areas across the project.
I/O and Configuration Documentation
Inputs, outputs, hardware setup, communication settings, and system configuration captured in one usable reference.
Critical Analysis and Pitfalls
Complex logic, undocumented sections, maintainability issues, potential errors, and areas that need extra care are clearly flagged.
Practical Reference for Your Team
Documentation designed to help maintenance teams, engineers, and future programmers understand the system without tracing through the whole codebase first.
Improvement Opportunities
Where useful, I also highlight technical debt, simplification opportunities, and areas where the code could be improved over time.
Who Is This For?
This service is designed for anyone who needs to understand, maintain, or modify a PLC system but lacks the documentation to do so confidently.
Existing Systems with No Clear Handover
You have inherited equipment, a facility, or a project that works, but nobody has properly documented how it works.
Contractor or Integrator Handovers
You need to take ownership of a system without relying on the original programmer every time something needs changing.
Legacy PLC Projects
The code is still important to operations, but the people who understood it have moved on and the comments are thin or missing.
Planned Modifications and Upgrades
You want to understand the existing structure before adding functionality, replacing equipment, or integrating with other systems.
Audits, Compliance, and Risk Review
You need a clearer technical picture of the current system to support audits, improvement planning, or operational risk decisions.
Reducing Key Person Dependency
Too much knowledge sits with one person or one site. Documentation helps spread that understanding and makes future support easier.
Beyond Documentation – Modification Support
If you’re planning modifications to the system, the documentation can be extended to include specific guidance on where and how changes should be implemented. I’ll analyze the existing code structure to identify the best integration points for new functionality, explain how the current architecture can support your planned changes, and highlight any constraints or dependencies you’ll need to work around.
This saves significant time during the development phase and reduces the risk of new code breaking existing functionality.
Ongoing Support
For clients who find ongoing technical support beneficial, we can discuss retainer arrangements or on-call support options. This might include answering questions about the documented system, providing guidance during modifications, or reviewing proposed changes before implementation. The goal is to ensure you get maximum value from the documentation and have expert backup when you need it.
Deliverables
You’ll receive professional documentation as a Word document (fully editable for your internal updates) or PDF (polished and ready for client handover or archival). The documentation includes PlantUML diagrams where helpful, flowcharts for complex sequences, and clear technical writing that your team can actually use.
For ongoing projects or situations where stakeholder feedback is valuable, I can provide living documentation through OneDrive with commenting enabled. This allows your team to ask questions, request clarifications, or provide additional context during the documentation development process.
How Scope Is Agreed
Start with a free, no-obligation discussion and a quick review of your project files.
Every documentation project is different, so I shape the scope around the size of the codebase, the level of detail you need, your platform, and how the finished documentation will be used by your team.
Typical scopes include:
Single machine or subsystem with straightforward sequential control. This might be a small packaging machine, single conveyor system, or basic mixing process with limited safety interlocking.
Typical turnaround: 1-2 weeks
Multiple coordinated machines or subsystems with complex interlocking and sequencing. Examples include production line sections, wastewater treatment processes, or batch control systems with state machine control and multiple communication protocols.
Typical turnaround: 2-4 weeks
Complete production lines or plant automation with multiple integrated subsystems, safety-critical systems, complex recipe or batch management, and advanced control strategies.
Typical turnaround: 4-8 weeks
How It Works:
Send me your PLC project files and a brief overview of what the system does. We will use that to discuss the scope, priorities, and the level of detail that will be most useful for your team. If it looks like a good fit, I will come back with a tailored proposal, clear deliverables, and a realistic delivery timeline.
Not sure where your project fits? The initial discussion is there to help us work that out together before you commit to anything.
Why Choose Me
I’m not just a technical writer – I’m an automation engineer who works daily with SCADA systems, PLC programming, and industrial control systems. I document and develop projects involving wastewater treatment plants, conveyor systems, and complex industrial processes for clients.
When I read your PLC code, I understand the engineering decisions behind it. I know why a particular state machine structure was chosen, what the interlocks are protecting against, and where the tricky edge cases hide. I document projects the way an experienced engineer explains them to a colleague – with context, reasoning, and practical insights.
I also create Asset Oriented Programming training content, so I’m constantly thinking about how to make complex automation concepts understandable. That teaching mindset carries through into every documentation project I deliver.
Book Your Documentation Quick Start Call
Use the calendar below to book a 30-minute discussion about your PLC project, the level of documentation you need, and what would be most useful for your team.
This is a free, no-obligation starting point. We can use the call to understand your system, your priorities, and the right documentation scope.