Information technology and communication (ICT) plays an important role as a catalyst for organisational development and innovation. However, old information systems that are known as legacy systems often expose organisations to the risk of business failure. These systems are not only impeding the advancement in technology strategy but also hindering the organisations’ business competitiveness. Nevertheless, legacy systems are essential in supporting critical functions in organisations including the public sector and could not be scrapped easily. These systems need to be given a new strength through modernisation to continue providing the best service in line with global trends. Modernisation is a complex task that involves several related aspects. In the context of the public sector, legacy systems involve a complicated information relationship, environment, and culture, while ensuring the citizens are of high priority. The implementation of a digital government represents the transformation of the public service delivery to the citizens that emphasises a citizen-centric design.
This study, therefore, aims to address this concern by reviewing the factors involved and suggesting a guideline in the form of a conceptual model to assist in the modernisation of legacy systems for a citizen-centric digital government. Data from the theoretical study were analysed using content analysis. The results show that the legacy systems’ modernisation comprised four main aspects, namely human, process, product, and organisation aspects, with related factors and elements. This model contributes as a reference for the public sector and provides overall guidance in performing legacy systems modernisation.