What is a software invention?

For each phase of the software engineering life cycle, one can distinguish the following four aspects that play a role in inventions:

• The capabilities to carry out this phase.
• The process that is used to produce the results of each phase.
• The tools that are used to support this process.
• The deliverable of each phase, i.e., the output produced in the course of this phase.

In principle, inventions are conceivable for all 20 phase/aspect combinations and for each phase/aspect combination, the three properties novelty, inventive step, and industrial applicability have to be specified. The final step in this analysis is therefore to investigate the IPR implications of each phase/aspect combination. This is achieved by addressing the following five questions for each phase/aspect combination:

• What is the state of the art and how is it described?
• What is the expected technical content of a described invention?
• What is the expected size of an inventive step?
• Who are skilled in the art?
• How does an infringement look like?

The properties novelty, inventive step, and industrial applicability are contained in these questions, where industrial applicability is contained in our technical content question. Observe that other authors make a distinction between physical utility, logical utility and application utility  [7], but we consider this as more geared towards the US patent system where usability is emphasized as a requirement rather than technical contribution.

By differentiating by life cycle phase it becomes clear how widely the answers to these questions can and probably will differ. A requirements engineer will need skills coming from psychology, sociology, business administration, formal specification and software engineering, while an implementor needs skills in programming languages, algorithms, software architecture, and software engineering. In other words software engineering is not a homogeneous skill but is based on several scientific and engineering disciplines.

This differentiation thus leads to more specific answers and may help to focus on described inventions. For instance, in a description of a new compiler technique it is unnecessary (or rather undesirable) to include usability arguments like ``this invention can be used in a personal computer, including a hard disk, CD drive, and a network connection ...'' as one so often reads in patent descriptions. Unless, of course, the invention is specifically related to these usability aspects. A typical example of the latter would be a compilation technique that is specifically aiming at reduction of power usage in mobile devices.

Figure 3: The Software Invention Cube (SWIC)

This analysis is summarized in Figure 3 that shows the Software Invention Cube (SWIC). It shows the five phases of the software engineering life cycle (Engineering phase/Technical aspect front plane), the four aspects of each phase (Technical aspect/Legal assessment top plane), and the five IPR questions for each phase/aspect pair (Engineering phase/Legal assessment right plane). In total $5*4*5 = 100$ combinations are contained in the cube that need analysis. We will now discuss some representative cells of the cube.