In the diagram below it can readily be seen that the URS, along with the regulatory requirements as detailed in GAMP 5, and the details of validation requirements as given in the VMP, come together to form a package from which the vendor can develop a fully legal, compliant and validateable  product.
Equipment qualification templates are available for the activities shown grouped in the two colours (orange and blue).  The blue color is the requirement for standard computer validation, while the orange color depicts the additional equipment qualification templates that are required when the process executed by the during equipment validation has been identified as critical.

The FDA regulators have decreed that software used in a manner that can affect the quality of the product, without leaving visible evidence, that damaged has occurred, must be deemed as critical to the quality of that product.

The regulators have further mandated that all such software be identified as such - and subjected; from concept to actual use, to Full Life Cycle Validation (FLCV) requirements.  This additional level of validation requires the addition of further validation GMP equipment qualification templates as portrayed in the diagram in orange.

The vendor therefore (be they in, or out, of house), must produce a Quality Plan that ensures the software development will follow a validation evolution similar to that shown in the diagram.  Your actual diagram must be planned and justified for the software system that you are proposing.

It is of paramount importance that your decision on software criticality is documented and that your Quality Plan (QP) is reviewed, approved by QA, the client & their  representative; all prior to initiation of the design stage.  Since these documents all form part of the equipment qualification-evaluation stage, you must expect regulatory inspectors to be interested in reviewing the content and the format of them.

All regulatory mandated protocols such as this Equipment Qualification protocol must be carefully prepared, with statements worded to preclude ambiguous and incorrect interpretations of the purpose of the statement. In addition there are quite separate requirements stipulated by the regulatory authorities. Documents presented to regulators during inspections that fail to satisfy these requirements, indicate to the regulator a lack of care and commitment on the part of the company. The exact opposite to what is required.
The FDA and regulatory authorities in general, are charged with increasing the level of compliance throughout the industry. This call for increased regulatory compliance, is driven by evidence that the industry is failing to match the standards set by other regulated industries.
Validation Online, have designed unique interactive documents for all validation activities such as VMP, URS, IQ, OQ, PQ, and many others. Understanding how to write a superb Equipment Qualification protocol takes time,  however at times the clever way forward it to use good quality templates. These documents have all been designed to be cGMP, compliant, along with incorporating the structures the regulators look for. These documents are realistically priced to ensure it is much more cost effective for companies to download documents as they require them, than individually author them.