Complementary use of ad hoc and post hoc design rationale for creating and organising process knowledge

Documenting the requirements engineering (RE) process using the ad hoc notation IBIS (Issue Based Information Systems) and analysing the complexity of the requirement model revealed that the process was not smoothly evolutionary, but involved occasional "crisis" points at which the model was reconceptualised, simplified and restructured. The IBIS base provided essential input for the reconceptualisation, simplification and major restructuring of the model. However, the locality of arguments and the lack of context in the IBIS notation led to difficulty in searching and retrieving desirable information from the large IBIS based. In this paper we investigate the supplementary use of the post hoc notation QOC (Question-Option-Criteria).