Selmo method in practice

🔷 Introduction to the Selmo Method: From Requirement to Operation

The Selmo Method (Sequence Logic Modeling) offers a new standard for the development of machine controls. Its goal is to model machine behavior deterministically, transparently and safely – and from that automatically executable control code, HMI operation and Documentation to generate.

Instead of classically manually programmed control code, Selmo relies on a formal modelthat describes all relevant processes, signals and states of the machine – in a clear structure, with automatic validation and complete traceability.

🔄 The process in Selmo follows a structured procedure:

1. Build PTF structure (Process flow – Technology – Function) → The machine is logically broken down into processes with a focus on the product and the process flows are derived from this. The technology and hardware requirements and specifications are checked for process capability. Functions are derived from the process and the technology.

2. Create structure for model formation (Plant - HWZ- SEQ) in coordination with the machine construction concept

3. Create process model → The sequences are modeled as a state model (Sequence) with zones and signals. Define system layer (bit control) → Each state is linked exactly with zones.

4. Export to PLCOpen XML & HMI generation → Control logic and user interface are automatically generated from the model.

5. Commissioning (IBN) and operation → The program is connected to the tested electrical system and interfaces, used in manual and automatic operation, and visualized in the HMI.

---

🧩 Why SIPOC?

To make this process understandable, plannable and verifiable for users, Selmo uses the SIPOC model as structured description method.

SIPOC stands for: Supplier – Input – Process – Output – Customer

📊 What does a SIPOC diagram show?

A SIPOC diagram describes clearly and compactly, what happens in a specific section of the process – and who delivers or receives what.

element	Meaning in Selmo
Supplier	Who supplies information or components (e.g., design, customer)?
Input	What data, requirements or signals are needed?
Process	What exactly happens in the process step?
Output	What is the result (e.g., a model, code, HMI)?
Customer	Who uses the result (e.g., operator, maintenance)?

---

🧭 Application in the Selmo Method

For the entire method – from the idea to the running machine – Selmo creates for each essential section its own SIPOC diagram for example:

• Requirement and specifications (PTF)

• process modeling

• Export/Import PLCOpen XML

• HMI generation

• Commissioning

These diagrams help to keep an overview, clarify responsibilities and make the process comprehensible to all parties involved.

🧭 Overview: SIPOC structuring along the Selmo Method

No.	Section	SIPOC focus	Description
1	Overall process – PTF	PTF = Process, Technology, Function	All necessary information, as before, is collected and formatted. Initial structure, definitions and analyses are made. Important for the process models later.
2	process modeling	Model structure according to Sequence, Logic, State, Zone, MXIC, CMZ	Construction and logic of the model
3	PLCOpen XML export/import	Interfaces to the controller	Handover to PLC / readback
4	HMI generation	User interface from model	Automated UI for manual/auto
5	Commissioning (IBN)	Model-based testing and approval	Simulation, step operation, testing