The ABC of User Requirements Specification (URS)
Report from the GDP Conference 2025, Lörrach
4 min. reading time | by Doris Borchert, PhD
Published in LOGFILE 09/2026
"User Requirements Specification also means: User specifies requirements!" Marisa Meinero (Elpro Messtechnik GmbH) pointed out at the beginning of her talk at the GDP conference 2025 about the purpose and objectives of the URS, the contents, and the best way to go about drafting them.
Dr. Doris Borchert, GMP-Verlag, has summarised the most important points for today´s feature.
What is a URS?
In the URS, the future user defines what the system should be capable of, but also what it is limited to. In addition to the (testable!) technical requirements, regulatory requirements should also be taken into account.
The URS serves as a tool for selecting suppliers and forms the basis for the supplier’s accountability.
In line with GAMPR 5, the URS is based on the V-model for qualification. It forms the starting point for the qualification process and serves as a reference document throughout the process.
Regulatory Background
This crucial lifecycle document is not a nice-to-have, but a regulatory must-have: a URS is explicitly required in a number of regulations, e.g.
- Annex 15 of the EU GMP Guide
- 21 CFR 211.63
- ASTM E2500 standard
- ISPE Good Practice Guide: Controlled Temperature Chambers
- WHO Technical Report Series 961, Annex 9 (Model guidance for the storage and transport of time- and temperature-sensitive pharmaceutical products)
The URS should focus on critical aspects. The specifications must be testable.
4 Steps to a Successful URS
WHO?
When creating a URS, all necessary subject matter experts should come together – keeping in mind the end-user’s needs! Team members are usually drawn from the fields of quality assurance (quality managers, SOP development), technical services (maintenance, engineering) and operations. The URS should be approved internally before the tender is launched.
WHAT?
The starting point for all considerations is the product’s critical quality attributes (CQA) and the associated critical process parameters (CPP). These give rise to the critical aspects that must be met. Together with further internal quality requirements and regulatory requirements, this provides the input for the URS. In addition, requirements and restrictions not relevant to GMP may also be incorporated into the URS, e.g. occupational safety aspects, industry standards, or site-specific requirements.
The output consists of critical design elements, the suitability and functionality of which are verified through testing. Risk analysis plays a key role at this stage.
HOW?
A URS needs a clear and well-organised structure!
- Each trade should be described in a separate chapter – for larger projects, it may also be advisable to have a separate URS for each trade.
- Central to each URS is a "Traceability Matrix" – it enables all numbered test points to be referenced at every stage of the qualification process.
- Requirements should be prioritised. The document should be kept as brief as suitable.
A URS must be SMART!
- Testing requirements must be specific, measurable, achievable, realistic, and testable (SMART).
- All test descriptions should be described in detail.
A URS needs a suitable format!
- The format needs to fit to the complexity of the system and the criticality of the product/process.
- Example: for ordering catalogue items, a technical data sheet and the order confirmation are sufficient; for planning a cold storage, a formal URS document and a detailed purchase requisition are needed.
WHAT FOR?
A good URS fulfils several goals:
- Part of the supplier selection process – comparison of suppliers, basis for awarding contracts and supplier accountability
- Basis for the work of the supplier – implementation in the functional specification document
- Basis of the materials list
- Basis of the risk analysis – identification of critical systems/functions and definition of the scope of qualification
- Verification – Testing requirements during commissioning and qualification
Tips for Implementation
In everyday life, whenever we make a purchasing decision, we intuitively draw up a ‘user requirement’ – whether it is for a new car, a laptop, or a household appliance. When creating a URS in a GMP environment, however, one should not rely solely on intuition, but should follow these basic rules:
- Start with drafting the document in good time.
- Involve all relevant experts in the generation process.
- Describe only one requirement per bullet point, so that each individual requirement can be clearly referenced later in the process.
- Define testable parameters and establish acceptance criteria so that compliance with the requirements can be tested objectively.
- Check the URS for duplicates to avoid unnecessary repetition and any potential contradictions.
- Leave the implementation of your requirements to the supplier (you specify WHAT is required; the supplier describes HOW they will implement it).
- Design the URS as a lifecycle document (this will require repeated adjustments).
- Use the URS for communication with various suppliers.
Do you have any questions or suggestions? Please contact us at: redaktion@gmp-verlag.de