TIME MODELLING FOR REQUIREMENTS AND SPECIFICATION ANALYSIS

摘要

Many new computer applications and emerging software technologies are based on a model of interactive computations. A remarkable share of those applications are truly time sensitive - meaning that it is essential to reason about time correctness of system's behaviour, and interactions between components in particular. The conventional software timing analysis is scheduling centred, well developed and pretty proficient. However, scheduling is applicable only in physical design and implementation stages of product development. Software production would be more economical provided that some obvious and/or subtle (e.g. timing correctness of interactions) time-related inconsistencies could be detected and eliminated earlier in product life cycle. Unfortunately simple time models conventionally used in computer science enable to reason about scheduling and performance estimation and leave timing of interactions untouched. This paper suggests that for reasoning about timing of interactions also, one needs to introduce a non-trivial time model (e.g. as in RT UML) and merge it with a model of interactive computation. The paper emphasises the necessity to merge the time model with the appropriate model of computations, and provides some examples.