Principles for Implementation of Design Standards

The design standards in AVEVA Marine have been implemented according to three different main principles.

1. The standard is completely "glued" into the code, that means, any required changes must be done by AVEVA and new programs must delivered when a standard of this type has been extended. Standard of this type is closed.

2. AVEVA Marine offers a set of tools (a "toolbox") adapted for the needs in certain areas. By combining these tools a customer may create his own standard in a certain area. Such a standard is open to the extent the toolbox is complete enough and it can be created and set up by the customer.

3. The standard is completely open, that means, a customer may set up his own standards without being restricted by the tools of AVEVA Marine.

In making a choice between these different ways of implementing the standards one has to consider a number of aspects:

• How often need the standard be changed? - If the frequency of new or changed standard is very low you may accept a standard that is less flexible.

• On the other hand: A standard that often need be changed, for example, between each project, need be open so that changes can be made rapidly and without dependency on resources outside the company.

• One should observe that there is often a trade off between flexibility and ease of use. An in-built standard is immediately available whereas a completely open standard may have to be set up or adjusted before it can be used.

• An in-built standard makes it easy to co-operate with other users of the application (and with your system supplier!). The in-built standard is common to all users and exchange of data and services can be done without problems. An open standard may cause troubles in such situations, for example, because two co-operating parties may have used different names for the same thing or - which is worse - the same names for different things. In any case, it is not enough to supply model data, relevant parts of the standard set-up need be transferred as well.

A compromise combining some of the advantages of all alternatives is that the system supplier - AVEVA - delivers information required for the set-up of an open standard. As long as customers stay with this standard it will to a large extent have the same benefit as the in-built standard but with an option for easy adaptation when needed.