3 Part 3: V-Modell Reference Tailoring
3.6 Process Modules
3.6.20 Enhancement and Migration of Legacy Systems
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Overview
Figure 38: Process module Enhancement and Migration of Legacy Systems
Purpose
The process module »Enhancement and Migration of Legacy Systems is intended to plan and execute measures for further developing systems in maintenance or for planning and executing the migration of the system to new technologies.
At a certain time, preventive maintenance may require a comprehensive further development of the system, e.g., due to extensive changes of functionality.
Systems will frequently degenerate in the course of time. Therefore, a »Legacy System Analysis is recommendable, but not indispensable for the further development of the system. Based on this analysis, the documentation of the system can be adapted or prepared anew. The effort required for the analysis varies greatly, depending on the system's degeneration level and on the quality of the existing system documentation.
The further development normally includes the incorporation of new requirements, which will have to be included into »Overall System Specification and integrated into the »System Architecture. If components of the system are migrated due to the new requirements, a »Migration Concept must be prepared. This is the case, e.g., if new requirements lead to changes in the »Data Model.
If a technical and functional revision of the system is required, a migration will normally be necessary. In case of a migration, the functionality of the system will be developed completely anew, while the data and interfaces of the legacy system will be integrated into the new architecture or platform.
In case of a migration, a »Legacy System Analysis shall be executed in order to determine if components can be migrated. The »Migration Concept will be based on this analysis. The new system will be developed anew in the process module »System Development. The »Migration Concept defines data and interfaces to be migrated.
Project characteristics that may include this process module