Principle 18: Purchase rather than Develop

Classification:  Application Principle

Statement: Component technology, application and services shall, as much as possible, be purchased off the shelf.

Rationale: Commercial products provide a greater longevity, supportability and are therefore more sustainable; whereas in house developments are likely to be constrained by the developer of the solution and their availability.

Acquiring commercial products provide a greater level of support, knowledge and upgradeability than can be afforded by internal developments.

Any new products procured for the enterprise, must be able to integrate with the existing architecture, unless it is replacing or significantly enhancing the current provision of service.  Otherwise software diversity increases and reduces the effectiveness of our ability to serve the needs of our customers.

Commercial Off-The-Shelf (COTS) products often provide a wealth of business logic, process modelling and workflows already developed or that can been altered to meet the enterprises requirements.  Roadmaps detail forthcoming improvements, in terms of security and functionality which ultimately benefit the planning processes; these business essentials are not present in solutions that are locally engineered.


  • This principle will require standards which support sustainability.
  • Formalised training programmes can be undertaken for both developers and staff managing the solution, thus enhancing both staff knowledge and expediting the benefits afforded to the business.
  • Following the initial set-up of the product, integration with additional systems should facilitate agile development.
  • Supplier and contract management must be included during requirement gathering activities.
  • Supplier and contract management must be active within the software and middleware management lifecyle