The case studies set out in the earlier chapters recognise March and Simon’s 1993 insights and themes. The categories which are discussed and developed provide explanations for the behaviour of four ﬁrms and provide new building blocks for the understanding of other ﬁrms in different circumstances. The emphasis is on empirical evidence, studying rule-based action and recognising the historical, social and interpretative contexts. Routines are deﬁned in this project as established, signiﬁcant, sanctioned and recurrent practices within organisations, and operational and strategic routines can be identiﬁed in each of the companies. Changes in routines can be explained using a recursive form of analysis.