# Post-Implementation ERP Software Development: Upgrade or Reimplementation
## 2 Implementation and Post-implementation ERP System Background
### ERP Post-Implementation Activities  
Over the last two decades, the primary IT system market supporting management in large and medium-sized organizations has been saturated. Currently, the main activity is to reimplement or upgrade the previously implemented system. However, most implementation methodologies focus on a phases approach to implement the ERP system. Companies (SME and large) are faced with ERP maintenance and development needs. The end of the implementation process opens the post-implementation phase. It is considered that IT may have a critical role in shaping ERP post-implementation adaption. In the paper [32], authors present control variables which include: IT turbulence, IT mindfulness, IT financial, adaptive agility, firm size and time since ERP implementation. It is assumed that the longer ERP has been deployed, the more likely a company adapts the ERP to their business needs. The paper analyzes action impact over time and its impact on the future decisions with ERP adoption.  
From the first days of the starting ERP system, CIOs mainly pay attention to maintain implemented solutions by receiving patches (fixes) for identified bugs or legal changes which impact the implemented ERP functionalities. Patches are easy to install and tests are essentially focused on the process part because it is usually built by providers on demand or forced by a legislator. Every few months, ERP companies provide updates for their actual ERP system. It consists of new functionalities, legal changes, and bug fixes which appeared after the last released package. Update installation is similar to the patches installation process, but it takes more time and demands complex tests across all implemented modules and ERP processes before launching into the production environment. Depending on the ERP provider, every few years they release a new version of a system. The upgrade installation process is often managed by the system provider or integrator. The upgrade process takes a few months; it mostly depends on ERP system and implementation procedures in  
\begin{table}
\begin{tabular}{l l} \hline \hline
**Vendor Name** & **Methodology** \\ \hline IFS & IFS Implementation Methodology, with these phases: Initiate Project, \\  & Confirm Prototype, Establish Solution, Implement Solution, Go Live. \\ \hline INFOR & Infor Deployment Method, with five phases of the implementation \\  & process: Inception, Elaboration, Construction, Transition and Optimization. \\ \hline MICROSGF & MS Dynamics Sure Step Methodology, with these phases: Diagnostics, \\  & Analysis, Design, Development, Deployment, Operation. \\ \hline ORACLE & A.I.M. (Applications Implementation Methodology), with these phases: \\  & Definition, Operations Analysis, Solution Design, Building, Transition, \\  & Production. \\ \hline SAP & ASAP methodology, with these phases: Project Preparation, Blueprint, \\  & Realization, Final Preparation, Go Live Support, Operation. \\ \hline \hline \end{tabular}
\end{table}
Table 2: Top ERP vendors’ implementation methodologies.  
companies. Upgrade is still only a technical process and all data are being automatically moved from an old to a new version. All activities are connected to on-premise installations on a client infrastructure or private cloud.