15. Design rules are about reusing knowledge of proven solutions for reoccurring problems. Reuse of solutions that give NNEC-specific characteristics is particularly important. These solutions should solve frequent and/or difficult problems, promote important system characteristics and/or improve the quality of the resulting product in a cost effective way.
16. Design rules consist mainly of the following three parts:
Context; describes under what circumstances the design rule is valid
Problem/Opportunity; is a description of the problem it solves or the opportunity it exploits.
Solution; is a description how the problem/opportunity shall/should be resolved in the given context
17. Design rules can give solutions on all levels, but it is anticipated that the produced design rules mainly takes care of the higher system levels (relating to the breakdown patterns in a system design) in order to avoid a cumbersome number of rules. If possible design rules shall be based on standards and/or NISP/NAF and will preferably be associated with as concept (generic concept of design).
18. A design rule package is a mechanism for packaging of design rules (by reference) within a certain domain or for a specific kind of system. The dependencies between design rules that are part of a design rule package shall be defined and minimized.
19. In today's knowledge oriented organizations it is very important to make sure that the knowledge of people is preserved in the organization even if the people change positions or leave the company. Design rules are important tools to be able to aid the process of managing this knowledge since they force documentation of knowledge in a structured way.
20. The use of design rules to document and package proven solutions is expected to speed up development, and reduce cost and risk, by reusing knowledge on how to solve recurring problems and by providing verified solutions to those problems.
21. Moreover, the use of design rules provide the means to coordinate development of different federated systems in order to make them network enabled and facilitate the evolvement of combined capabilities. Another important aspect is also that design rules aid organisations in creating a common understanding of the problems and challenges they are facing.
22. In order for design rules to have effect in an organization there must be a framework which describes what design rules are and how they shall be used, i.e. this document. Design rules will also affect the way solutions are described and must be an integral part of the architecture description framework.
23. Another important thing to remember is that design rules will affect the way we work, thus putting new requirements on the processes and people within our organization.