The first step is to understand the context in which the IS success evaluation is being conducted (Farbey, Land, & Targett, 1993). Adelakun and Jennex (2002) classify the most effective approaches to IS evaluation into four major categories: financial, functional, strategic measure, and subjective measure. Stockdale and Standing (2008) argued that the goal of an evaluation is to assess value and measure success.
According to Al-Mashari, Al-Mudimigh, and Zairi (2003), ERP projects can be considered successful when: (1) there is a match between the ERP system and the stated objectives, (2) the system is implemented within time and on budget, (3) users’ attitudes toward the system are positive, and (4) the system matches users’ expectations. Chun-Chin et al. (2008) proposed a study that adopted performance measures, such as data accuracy, output, system accuracy, and usefulness from the relevant literature. The authors noted that many organizations put their attention on selection and implementation but fail to evaluate the effectiveness of the ERP systems.
Many researchers have considered end users’ satisfaction and acceptance, starting with Davis’ (1989) model, which introduced the Technology Acceptance Model (TAM), which provides an understanding of the impact of external variables on attitudes and intentions to use of an ERP system. The effects of an IS in this model are determined by its perceived usefulness (PU) and perceived ease of use (PEU). The model argues that external variables indirectly affect attitudes toward usage, and in turn lead to an actual system use by the influence of PU and PEU.
TAM was later extended and called TAM2; this extended model added subjective norm as another important factor affecting adoption decisions of users. The model has been tested to prove that PU and PEU are the two main fundamental theoretical constructs.