**1. Introduction**

The world is becoming a small society which is totally blended with technology, therefore, prompt services technology need to be implementing in the society to meet its demands. These services are becoming y complex in volume and type to meet society's increasing expectations out of these services. Due to the advancements in ICT and digital transformation as well as the growing rate of internet and mobile technologies users has led to the emergence of new business models causing huge and rapid changes in service production as well as users expectations and behaviors. The impact was even dramatic in the public sector and e-government as its substantial growth was evident in last two decades to describe how ICT is utilized to boost the efficiency and quality of public administration in a government setting.

e-government is regarded as second revolution in public management/ administration due its substantial critical role in transforming the way public services as well as the relationship between government (service providers) and citizens (service users) [1]. As e-governments thrive to offer their best services with highest level of quality, they rely on the quality and the usage by service

users [2]. To achieve highest level of trust between user/citizens and governments, quality is regarded as a key factor in this formula. As the main objective of e-government to make their services accessible and access the information smoothly and easily. The governments needs to continuously invest in their information technology, operations and infrastructure to assure reliable communication which ultimately satisfy the high quality service expectation of users/citizens [3].

An extensive amount of research was conducted from various domains (services, marketing, information systems, e-government) to measure service quality and various scales and models, frameworks were also proposed by different scholars as summarized by [4, 5] covering the domain of service quality, e-service quality and e-government quality.

In this course of study, a systematic literature review (SLRs) research methodology was carried to explore all relevant quality models, methods, factors, indicators, measures used in the process of maintaining the quality of service which satisfies the users/citizen satisfaction and loyalty level. The main purpose of this chapter is therefore to draw a roadmap as per existing studies of key elements for e-service quality dimensions which in return plays a significant role in enhancing overall service offering and usage by service providers and service users. As a result, this research will pave the way to put into the context in preparation for more studies to validate the presented quality factors in various service domains.
