16.11.2021 | LOGFILE Feature 43/2021

Excerpt from the GMP Series E-Book “A Pharma Guide Planning and Constructing Cleanrooms

Cleanrooms: The Path from Concept to Qualified System

Cleanrooms: The Path from Concept to Qualified System

6 min. reading time | by Harald Flechl


Good Engineering Practice (GEP) for procurement

Beginning from the definition of the User Requirements Specification (URS) the planning phase is subdivided into four stages:

  • Pre-planning
  • Concept planning
  • Fine planning
  • Execution planning

The implementation phase includes three stages:

  • Execution/construction
  • Commissioning, training
  • Qualification

This scheme is based on established Good Engineering Practice (GEP) principles. It should be noted that pharmaceutical authorities also recommend GEP as a methodology for the design of pharmaceutical plants.

The essential elements of GEP in the conception, planning and construction of pharmaceutical production facilities are summarized below:

  • Observance of local construction laws and other relevant regulations
  • Knowledge of pharmaceutical regulations
  • Knowledge of relevant regulations and pharmaceutical guidelines
  • Observance of the principles of cleanroom technology according to the current state of the art and science 1
  • The development and evaluation or weighting of all requirements together with the user based on the requirements of the manufacturing process
  • The consideration of process, material and personnel flows in order to eliminate or at least reduce possible contamination risks
  • The application of value analyses and risk assessments in the selection of options.

All these requirements are handled step-by-step and iteratively and are included in the URS. They form the basis for further qualification steps as a precondition for pharmaceutical use. Annex 15 of the EU GMP Guidelines also describes, among other things, the requirements for qualification of plants and equipment.

In practice, it has proved successful to provide a room book as an appendix to the URS for cleanroom construction and also to use it for checking the FDS. In the context of qualification, it can also be used as a reference document for the verification of the individual qualification steps.

The Functional Design Specification (FDS) provided by the supplier specifies how the URS will be implemented. The FDS is then checked for plausibility and fulfilment of all the requirements listed in the URS and adapted, if necessary, or rejected.

The terms "URS" and "FDS" are less common for cleanroom construction and utilities engineering (electrical, ventilation, air conditioning, compressed air, etc.). The planner usually creates a list of specifications with functional descriptions, quantities and services on the basis of the specifications in the URS. This performance specification list is regarded as equivalent to an FDS and does not have to be "translated" into a new document.

Figure 3.E-3 The path from concept to qualified system

1     Standards and other guidelines are to be considered only as recommendations and do not always represent the current state of the art.


Harald Flechl


Harald Flechl
Air Conditioning Technician – Clean Room Technology
E-Mail: flechlh@chello.at

GMP Series E-Book “ A Pharma Guide to Planning and Constructing Cleanrooms

GMP Series E-Book “ A Pharma Guide to Planning and Constructing Cleanrooms

Excerpt from the GMP Compliance Adviser

Get to know how to successfully get through all steps of planning and constructing cleanrooms.

This E-Book covers all aspects you have to consider. For example, it offers expert knowledge on:

  • Laws, rules and guidelines
  • New technologies for project planning
  • Example of a risk assessment for surfaces
  • etc.

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