What Is A User Requirements Specification [URS]?

This article continues the discussion on User Requirements for Good Engineering Practices (GEP).

Read the first article in this series: The Basics of Good Engineering Practice: GEP-101

This second installment presents the importance and value of a well-written and meaningful “User Requirements Specification” (URS) document, as the starting point in achieving and managing the quality of an engineered system. 

Simply put, the URS document enables an organization’s Users and key stakeholders to begin with the end in mind to ensure that the expected engineered system is actually achieved; the first time.  This is possible because the requirements specified in the URS document support the design, construction, commissioning, and qualification of the system.  The URS document establishes the qualification requirements needed to verify that the system is properly installed, set-up, and operates to meet the performance expectations of the system.

Designing, constructing, qualifying and then operating and maintaining an engineered system that achieves the user requirements defined within a URS reduces the wide variety of risks that may impact the delivery of such a project, and helps to consistently deliver engineered solutions that minimizes the use of resources, time, and money.

 User Requirements for Good Engineering Practices

In ISPE’s Good Practice Guide: Good Engineering Practice document, it states that:

“Regulated companies should have established methods for developing and reviewing a formal User Requirements Specification (URS), capturing both the fundamental aspects and scope of the users’ requirements.  Users should be involved as much as possible in this process.  As a minimum, users should be required to review and approve these requirements. Requirements should be objectively stated such that they can be verified during testing and commissioning.  Alignment with objectives of any company strategy or master plan should be confirmed.”

Key words and concepts in the above statement that form the foundation of an effective URS document include:

• Established and formal;
• Captures fundamental aspects and scope of users’ requirements;
• Users are required to review and approve;
• Objectively stated;
• Verifiable during testing and commissioning (and qualification) to assure  installation, operating, and performance quality; and finally,
• Aligned with company objectives and strategy.

The utility and value of a well-written URS document (described in the next section) as an effective tool is realized throughout the entire engineering process; especially at the point of turnover of the engineered solution to the User for its intended use.  At this crucial point, the URS document provides Users with a formal mechanism to confirm that their specifically identified, reviewed, and approved requirements have, in fact, been achieved by the final delivered system.

 CT’s “Requirements Categories”

Compliance Team has developed, and routinely uses a comprehensive and highly flexible and adaptable URS template that addresses all of the above mentioned elements of a sound URS document.   CTI’s time-tested; URS template is easy to use for any type of engineered process or facility.  

CTI’s URS template captures the full scope of all user requirements; tracks reviews and approvals; and allows for only objective (measurable, verifiable, repeatable) user requirements.

The objective of the URS document is to define the “critical” user requirements to be satisfied by the final engineered and installed system to meet the User’s intended use of the system.   Some key definitions include:

A.    Critical Aspects (CA): Functions, features, abilities, and performance or characteristics necessary for the manufacturing process and systems to ensure consistent product quality.

B.    Critical Quality Attribute (CQA): A property of a product or output of the process that is reflective of the process performing as expected. Critical quality attributes correlate to critical process parameters.

C.     Critical Process Parameter (CPP): A process parameter that can affect the critical quality attribute (s) of the product / process / unit that must be controlled within a pre-determined range or specification criteria.

These critical aspects, attributes, and parameters form the basis of the key requirements.  The “Requirements Categories” that establish the user, functional, and design requirements should include:

1.          Supplier / Documentation Requirements

2.          Equipment Requirements

3.          Utility Requirements

4.          Physical Requirements

5.          Operational / Performance Requirements

6.          Control and Data Acquisition Requirements

7.          System Construction / Installation Requirements

8.          Regulatory Requirements

9.          Environmental, Health and Safety Requirements

Note: Each user requirement should be uniquely numbered as seen in Attachment A.

Conclusion

Because CT’s URS template document comes with pre-established “Requirements Categories” it is an excellent tool to help Users focus on requirements broken down by categories.  This focus greatly assists organizations get started in the engineering process; without wasting time, resources, and thought on what to do first.  With CT’s URS template document, the starting point and path is already defined.

Additional utility and value is created when the URS document is incorporated into contract and purchase order documents.  This practice delivers significant value to clients because it ensures consistency and accuracy and greatly minimizes the risk that an important requirement is not properly met in the delivered solution.