Within the DMS BCS delivery process there are several levels of customer: The primary customer is the end-user of a telephony feature while the secondary end-user is a telephone operating company. Customers within BNR such as designers who reuse software written by others are not really considered as customers because they are not an obvious source of revenue. Consideration of the individual designer and project teams as the customer for software reuse could result in substantial development savings. The benefits of reuse, particularly in the short-term, are difficult to visualize in a production environment driven by short development cycles and limited market windows. The initial impetus must be driven by a global-corporate perspective of the benefits.
From a designer perspective, there are a number of reuse inhibitors that must be addressed before a cultural evolution can proceed. First we assume that the distinction between reuse producers and reuse consumers is important - probably to the extent that designers designing for reuse will be different from those designing with reuse. Why should this be the case? While it is possible to specify a methodology for building with reuse, only general guidelines can be given for design for reuse. The incentives and cultures appear to be different. For example, application designers can follow a general methodology for design with reuse, i.e.they can design and build robust software reusing components (following the principles of software engineering, e.g. reviews, inspections, testplans). Our experience has indicated that designers, require extensive application or system experience and motivation for effective reuse contributions. Application designers are also driven by the narrow market windows which govern their deliverables. Usually they don't have time to experiment or consider applications beyond the scope of their current deliverables. Additionally, no time is available to support and educate other designers since this would reduce the time available for feature development.
Experience and specialized expertise are essential for designers to be considered as reuse specialists. For reuse to be explicitly provided, it must become a deliverable with specific cost objectives, e.g. internal client groups with target application areas and cost benefits. This is done within BNR and is partly due to the critical mass of both design staff and feature families (large application areas) that can benefit from reuse. As the reuse methodology matures, a culture will develop that will promote reuse on more of a day-to-day basis. However, this culture will only become evident during the transition between the current regime of reuse-by- convenience and a regime where reuse-by-process is standard.