This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Despite numerous efforts to integrate business and IS strategic plans, organisations are not delivering the expected benefits from IS investment. To address this issue, IS alignment research has discussed extensively the idea of establishing two-way commitment between business and IS managers. This commitment, however, has proved to be difficult to achieve at strategic level and consequently difficult to transmit to lower levels within organisations. Given that current literature has identified the main factors affecting IS alignment, this research extends the analysis of those factors to tactical and operational levels to develop a model tha...