The evaluation of enterprise resource planning (ERP) systems for performance enhancement in public sector organizations is a crucial concept due to its different nature from private concerns. The objectives of this paper are to explore the relationship of the common performance enhancement factors in the context of the gap between the real and ideal ERP performance of public sector organizations in Pakistan and to explore the overall difference between the ideal and real ERP performance in those organizations to provide some guidelines to the public sector in Pakistan. The difference between the ideal, i.e., the expectations of the organization before implementing ERP, and the real performance of ERP in Pakistani public sector organizations is the main source of identifying the impact of common performance indicators on the ERP overall performance. Different researches have been conducted to find the critical success factors in various areas of ERP, like strategic, managerial, technical, and contextual factors, but the impact of the common factors that affect the ERP performance as a whole has never been investigated. Little research has been conducted on the performance factors, especially in the large-scale public sector organizations in developing countries like Pakistan. We performed data analysis considering descriptive statistics, reliability analysis, correlation analysis both in ideal and existing situations, and paired sample t-test. We found, based on the paired sample t-test, that there is no gap between the ideal and existing ERP systems for time and database variables, but there is a gap between the ideal and existing ERP systems in functionality, user-friendliness, flexibility, reliability, service, vendor support, and the overall performance of the ERP system deployed in the government sector of Pakistan.