Modification free extension of standard software

In software development the companies create new versions to enhance the solution according to the market requirements and own ideas. On the other hand the ready to use products are not always stable and offer the promised features, so the software should corrected generating new builds and sub versions. These repaired features are delivered as patches or bundles (packages) to the customers. In case of office or home applications the patching or versioning not considers the customers' requirements, just apply the patches and keep or not the configuration. The integrated software, like an ERP solution has generally client/server architecture and is very complex not to consider the configurations. These solutions many times need customer side, project based extensions on different levels like database structure, data-model, functional model, programming, user interface, etc. These extensions should be kept and in some cases redesigned after applying patches or upgrading to new versions. Our paper gives direction how we can build into a software such capability to handle the sustainability and long-term maintenance.