535 Copyright © 2019, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. Chapter 39 DOI: 10.4018/978-1-5225-7362-3.ch039 ABSTRACT Turbulence in the businesses environment is on the increase. Therefore, businesses are obliged to re- spond to that environmental uncertainty. Strategic information systems planning (SISP) supports this efort. Information systems are connected with business strategy, management skills, decision making, and aim to increase competitive advantage. Previous studies have examined the efect of SISP phases on success. Also, other studies have concluded that there is a positive relationship between SISP and frm performance. The aim of this chapter is to present a holistic approach in order to investigate the signifcance of SISP process, to highlight phases that contribute to a greater extent of success, and to draw conclusions concerning the successful implementation of digital strategy in frms and especially in SMEs, which are an important part of the economies of developing countries. INTRODUCTION In this day, turbulence in the businesses’ environment is on the increase. Therefore, businesses are obliged to respond to that environmental uncertainty. Information Systems (IS) and Strategic Planning support this effort. IS are connected with business strategy, management skills, decision making and aims to increase competitive advantage (Zubovich et al., 2014). Researchers have focused on the pro- cess of Strategic Information Systems Planning (SISP) since 1970. The purpose of SISP is to support the goals and the business strategy, through IS. Furthermore, SISP helps businesses to innovate, create new products, reduce costs and enhance relationships with customers (Kamariotou & Kitsios, 2015, Ullah & Lai, 2013). The process of SISP contains five phases, which are strategic awareness, situation analysis, strategy conception, strategy formulation and strategy implementation planning. These phases help businesses not only to define IS strategy but also to develop IS. Strategic Information Systems Planning Maria Kamariotou University of Macedonia, Greece Fotis Kitsios University of Macedonia, Greece