In: Data & Knowledge Engineering 6 (1991) 469-477, N. Holland Elsevier Science Publishers BV. 1991.
Abstract: The paper explores how time-related concepts can be treated in a strictly causal way. Clocks in a local, global and regional variant are modelled within a causal frame. Perhaps the most critical use of clocks is for defining deadlines. To analyze their meaning, two relevant distinctions ar made: (1) contingent vs. strict deadline requirements and (2) descriptive vs. prescriptive part of a deadline requirement. A deadline delay paradox that appears on a seemingly semantically invariant inversion of the requirement specification can be dissolved on the basis of these distinctions. The conceptual frame for discussing causality is taken from Petri net Theory.