PTF operating procedure – Process, Technology, Function
1. Purpose
This procedural instruction describes the structured execution of the PTF process for the formal, traceable and safe definition of machine and plant behavior.
Legal / normative
from requirements and task definitions clearly defined, testable process models to develop,
the technical means (technologies, components, interfaces) to define,
and the functions to formally describe that implement the behavior.
The result of the PTF is a complete technical description of a system – logical, functional and documented. This forms the basis for:
Design and control development
Simulation and commissioning
Safety and risk analysis
Documentation, standards evidence and acceptances (FAT/SAT)
2. Scope
This PI applies to all projects and systems where:
machine or plant behavior is specified,
automation, control or programming is required,
and a formal documentation and traceability is demanded.
It is to be applied for:
machines, partial plants, stations, modules
new plants, conversions and functional changes
3. Objective of the PTF process
The PTF process ensures that:
Processes (P) are understood, described and formalized,
Technologies (T) are unambiguously specified, safe and standards-compliant,
Functions (F) are traceably described, reusable and testable,
Dependencies between P–T–F are documented and released,
the entire plant definition is consistent, safe and auditable.
4. Terms (Core concepts of PTF)
Process (P)
Describes what happens – the logical sequence, the behavior and the states.
Technology (T)
Describes with what it happens – the technical means, interfaces and safety features.
Function (F)
Describes how it is implemented – the logical or physical effect of the technology in the sequence.
PTF documentation
Collection of all documents (P-, T-, F-sheets, matrices, diagrams, test protocols).
PTF release
Official confirmation of completeness and correctness by responsible specialists.
5. Roles and responsibilities
Project manager
Initiation of the PTF, coordination of all disciplines, approval of results
Process planner / chemical engineer
Description of the process flow, product and process analysis
Automation Engineer
Definition of functional logic, control sequences, interfaces
Safety Engineer
Assessment of risks, safety functions, PLr/SIL
Design / Mechanical / Electrical engineering
Provision of technical data, zones, component lists
Quality management / Documentation
Archiving, version control, release management
6. Process description of the PTF process
Overview
7. Process steps in detail
7.1 Process description (P)
Objective: Fully understand the process and describe it formally.
Contents:
Product, process, operator, logical sequence
Process flow diagram, SIPOC, states and transitions
Reactions, deviations, safety behavior
Tools / methods:
SIPOC diagram
Process flow diagram (Miro, Draw.io, Visio)
State description (Excel/Word template)
Risk analysis according to ISO 12100
Results:
Process description (P-document)
Process matrix (states, transitions, signals)
Risk and function analysis template
Release criterion: Process flow unambiguous, all states described, risks assessed.
7.2 Technology analysis (T)
Objective: Define the technical means by which the process is realized.
Contents:
Identification of the technologies used
Components, interfaces, safety functions
Parameters, limits, diagnostics
Standards, regulations, technical approvals
Tools / methods:
Technology data sheet (T-template)
Technology matrix (T-matrix)
Interface description
Applicable Standards Page (standards list)
Results:
T-data sheets per technology
T-matrix (overview of all technologies)
Interface and safety documentation
Release criterion: All technologies specified, interfaces checked, standards compliance ensured.
7.3 Function description (F)
Objective: Formally define and document logical and physical functions.
Contents:
Description of the function (purpose, effect, behavior)
Inputs, outputs, parameters, limits
Safety and diagnostic functions
Test criteria and test cases
Assignment to process and technology
Tools / methods:
F-data sheet (function description)
F-matrix (linking P–T–F)
F-test plan
Results:
Function data sheets
Function list / library
Test and test protocols
Release criterion: Each function uniquely identified, tested, versioned, traceable to P–T.
7.4 PTF review and release
Objective: Ensure that all elements are described consistently, completely and correctly.
Check points:
Process logic complete and contradiction-free
Technologies released in accordance with standards and safety engineering
Functions complete and testable
P–T–F linkage consistent
Tools / methods:
PTF review checklist
Deviation log
Change management (change control)
Results:
Release protocol
Change report
PTF release (versioning)
7.5 Handover to engineering / modeling
After PTF approval the following takes place:
Transfer of the defined contents into engineering tools (e.g. CAD, PLC, HMI, simulation)
Use of PTF data as input for:
Automation and control (PLCopen XML, function blocks)
Risk analysis / validation
Documentation / CE process
8. Documents and templates
PTF procedural instruction (this document)
Process description and flow
PDF / DOCX
P-data sheet / P-matrix
process description
XLSX / DOCX
T-data sheet / T-matrix
Technology analysis
XLSX / DOCX
F-data sheet / F-matrix
function description
XLSX / DOCX
Applicable Standards Page
Standards overview
XLSX
PTF checklist / review protocol
Release procedures
DOCX
PTF release protocol
Signature sheet
9. Tools and systems
Tables & templates (Excel, Word, Visio, Miro, Draw.io)
Version control (SharePoint, PLM, Git, engineering server)
Engineering tools (e.g. EPLAN, Codesys, TIA, AutomationML)
Risk analysis tools (ISO 12100 templates, Excel)
PTF database or Selmo Studio (model-based integration)
10. Change and release procedures
Release levels:
P release
Process flow and behavior
Process planning
T release
Technology and standards compliance
Automation / Safety
F release
Functional logic and tests
Control / QA
PTF overall release
Completeness, version, handover
Project management
Change classes:
A: New function / technology / safety-relevant change → review mandatory
B: Parameter or detail change → must be documented
C: editorial / text correction → version update
11. Results of the PTF process
Complete PTF package
All P-, T-, F-documents complete, released, versioned
Process description (P)
formal process model / flow description
Technology analysis (T)
defined technical means, interfaces, standards
Function description (F)
defined logical functions and test conditions
PTF matrix
Overall overview of the P–T–F assignments
Release protocol
Documented acceptance / signatures
Change documentation
Traceability of every change
12. Benefits and achievement of objectives
By applying the PTF procedural instruction the following arise:
✅ Structured, testable project bases ✅ Safe, traceable process and function definitions ✅ Standardized technical documentation (auditable) ✅ Efficient collaboration between disciplines ✅ Basis for code generation, simulation, validation ✅ Evidence of systematic risk minimization according to ISO 12100
13. Approval & version control
1.0
DD.MM.YYYY
Initial version
Engineering
Project management
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