🧭 Selmo process modeling in the overall project timeline

1. Starting point: The problem in classical projects

In conventional machine projects a central problem arises:

• The process is understood – but not described formally.

• The requirements are documented – but not implemented unambiguously.

• The code works – but is not explainable or verifiable.

This leads to:

• Deviations between process and software,

• Increases in time and costs during commissioning,

• Black-box code, which no one can trace,

• missing evidence for standards, safety and quality.

Selmo solves exactly this problem, by generating from the process description a formal, deterministic and documented process model – visible, verifiable and automatically executable.

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2. Role of process modeling in the project flow

Process modeling is the bridge between definition (PTF) and implementation (software & commissioning). It translates requirements into an executable, traceable and documented machine behavior.

Customer requirement (problem)
   ↓
PTF – Process, Technology, Function (What is needed?)
   ↓
Selmo process modeling (How does it work?)
   ↓
Code / HMI / Documentation (How is it executed?)
   ↓
Digital twin / Commissioning (How is it tested?)
   ↓
Operation / Service (How does it remain traceable?)

Central statement:

The PTF describes what what the machine should do. Process modeling shows how that it does so deterministically. And the code executes it formally correctly.

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3. Why process modeling is necessary

Problem statement	Selmo solution	Benefit
Unclear translation of requirements into software	Formal model as an intermediate layer between PTF and code	No interpretation errors
Individually written logic, not verifiable	Model generates deterministic, verifiable code	Traceability and verifiability
Missing structure / dependencies between processes	Structure model: Plant → HWZ → SEQ → Zone	Transparency and reusability
Lack of safety / standard compliance	CMZ and MXIC rules as part of the model	Safety formally guaranteed
No documentation of the code	Automatic documentation (system, logic, safety layer)	CE- and audit-capability
Late error detection	SoftFAT / Digital Twin integration	Early validation, time savings
Dependence on individual programmers	Standardized, formally defined modeling	Company-wide reusability

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4. What happens in the process modeling?

The process modeling builds on the results of the PTF and systematically translates them into a formal machine model:

Phase	Activity	Result
1. Structuring	Create plant, zones (HWZ, SEQ, Zone)	Logical machine structure
2. System layer	Define signal behavior (bit control: 0, i, S, M)	Automatic behavior documented
3. Logic layer	Model states and transitions	Process logic visible and traceable
4. Parameter layer	Define values, times, tolerances	Flexibility through configurability
5. CMZ / MXIC	Define safety and manual operation behavior	CE-compliant safety
6. SEQCross	Synchronize processes between sequences	Modular, scalable structure
7. Validation / Test	Run simulation or SoftFAT	Error-free, tested logic
8. Generate output	Code, HMI, documentation, safety reports	Complete, verifiable machine output

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5. Why process modeling is placed at this point in the project

Time	Task	Result / Goal
After PTF approval	Transfer all PTF data into the model	Ensure complete, verified requirements
Before PLC programming	Create the formal process model	Deterministic code can be generated automatically
Before SoftFAT / Simulation	Connect the model with the digital twin	Virtual commissioning possible
Before commissioning (IBN)	Check code, HMI, safety	Time gain, risk minimization
In operation / service	Use the documentation, HMI, parameters	Transparent maintenance, training, optimization

Central importance:

Process modeling replaces the unstructured programming process with a formal, documented and traceable modeling process.

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6. Benefits in the overall project (from problem to added value)

Perspective	Before Selmo (problem)	With Selmo process modeling (solution)	Direct benefit
Project management	Lack of transparency, hardly verifiable software	Complete, documented model	Predictability, safety, demonstrability
Process owner	Process is not implemented exactly	Logic and behavior visibly modeled	Traceable implementation
Mechanics / Electrical	Poor coordination with controls	Structure reflects real machine	Better coordination
Software / automation	Individual codebase, unclear status	Standardized modeling, automated code	Quality, reusability
Quality / CE	No evidence of behavior	Formal documentation, safety layer	CE- and audit-capability
Operations / Service	Black-box behavior, no clear diagnosis	HMI & logic are congruent	Fast fault localization
Customer / Operator	No traceability of behavior	Documented, tested machine model	Trust, transparency, safety

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7. The “why” at the core – the benefit from the customer’s perspective

• Why model instead of program? Because models are verifiable, explainable and reusable – programs alone are not.

• Why now, after the PTF? Because here all requirements are validated before they are implemented technically – changes are still inexpensive, errors still reversible.

• Why relevant for all participants? Because the model connects all disciplines: mechanical, electrical, process, software, quality and operations.

Process modeling turns isolated specialist departments into a consistent system understanding. Everyone sees the same thing – in a formal, unambiguous language.

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8. Result in the overall context

Process modeling = formal implementation of the PTF results → It generates the “digital twin of the behavior” of a machine – even before the hardware actually exists.

This creates:

• A model instead of an interpretation,

• Documented code instead of individual logic,

• Visible behavior instead of a black box,

• Reproducible engineering instead of one-off knowledge.

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9. Conclusion – Why & What

Why: Because every project needs clear, formal and verifiable logic. Selmo ensures technical and normative correctness from definition to execution.

What: A complete, formal, documented machine behavior – logical, safe, deterministic and verifiable.

How: Through the standardized process of Selmo modeling – from the PTF through logic, system, parameters, safety and HMI to the code.

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With the PTF knowledge is collected – with the process modeling knowledge is applied.

It is the moment when requirements become reality – precise, safe and traceable.

This aligns the entire Selmo engineering process thought from the problem and toward documented technical excellence.