Current systems analysis examines existing systems that support the business area and are to be replaced by, interfaced with, or reused by, new systems. The technique focuses on current data structures and procedures and the support provided by existing systems to business processes.
Current systems analysis focuses on entity types and business processes. It is typically performed separately, but in parallel with, data and activity analysis. However, in a small development project, it may be useful to analyze a current system together with data and activity analysis. This provides continuous confirmation of the business model and development project decisions to replace or reuse current procedures and data stores.
In a large development project, a survey of current systems may be performed early in analysis. However, where it is planned to reduce the initially defined project scope to support a more focused project, it may be more practical to postpone a more detailed analysis until the scope of the development project has been refined.
Where it has been identified that a number of current systems collectively support several business areas, for instance, during planning, then current systems analysis may be assigned to the highest priority project, or may even be planned as a separate project which is then coordinated with all the affected system development projects.
In all of these scenarios, the objectives of performing current systems analysis before completing analysis, are to:
Analyzing current systems helps completeness checking during modeling, and in model confirmation at the end of Analysis. This verifies scope and identifies any omissions.
This may involve planning to replace all or part of the current systems, or interworking with them. Especially where data is to be reused, it may involve evaluation of the accuracy and consistency of data in
current data stores.
Identifying differences between existing data structures, system use of data, and activity dependencies helps in developing strategies to resolve conflicts that may occur when data from existing systems is converted or is used by new systems.
Current systems analysis techniques produce a complete representation of data, processes and their interactions by developing one or more current system business models.
Systems that represent a compatible view of the business may be combined into a single model. This model can then be used as the basis for completeness checking, transition planning, and preparation for conversion and interfacing procedures.
If data in existing data stores is to be reused (such data is therefore sometimes called "legacy data"), then the model may become part of a new system, which may exploit client/server techniques for instance, to make current data available through server procedures to new client procedures.
The techniques employed are those of reverse engineering. These techniques can also be applied to re-engineering a system to change the technology used, or applied to analyzing, selecting, and planning the introduction of a packaged application.
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