Inherent virtues, allied to proper in-the-large support, make the transformational paradigm a potent weapon for the software engineer. A taxonomic model of software transformational space is sketched. The main vertical in-the-large transformations needed for Jackson system development are described; these are provided within the CASE workbench PRESTIGE.>

The PRESTIGE workbench is an integrated CASE (computer-aided software environment) intended to provide full implementation support for Jackson System Development (JSD). JSD is an operational software development method, and thus implementation in JSD is essentially a transformational process. The main objective is to offer a generalized transformational facility that the JSD implementor can apply as desired to suit the needs of any particular implementation scenario, although a default implementation capability is also provided. Many of the transformations required can be automated, and the so-called 'inversion' transformations play a pivotal role in that capability. The author addresses a variety of technical issues that need to be considered in providing a user-controlled inversion facility within the PRESTIGE environment. The issues discussed include schedulerless implementation, rough merges, multiple inversion, buffering, and write inversions.>

A taxonomy is advanced that classifies prototyping in software engineering according to its application to different stages of the software development process. The prototyping categories are termed early, middle, and late. The rationale and tool support for each category are described and compared. Whereas early prototyping is the traditional perception of the activity, middle and late prototyping are separate categories that are supported by operational methods of software development. In particular, late prototyping evaluates performance, rather than functionality and interface, and is made cost-effectively feasible by operational methods.>