functional Specifications

[Former Member]

In preparing Functional specs,what are DFD / ERD ,what are their full forms and what is GAP analysis.

[RichHeilman]

Gap Analysis referrs to the process in which one analyzes a complete business process from start to finish, places where the flow is broken or incomplete is referred to as "Gaps". In some cases, custom programs must be developed to fill in those gaps.

Regards,

Rich Heilman

[uwe_schieferstein]

Hello Anurag

DFD means "Data Flow Diagrams". These diagrams display how the data is "flowing" along the process. Usually you have a data source. The data source is the input for a function which somehow processes the data and its output flows next to a data sink.

ERD means "Entity Relationship Diagrams". These diagrams basically show how the data are stored in DB tables and their relations (e.g. 1:n, 1:1, 1:c).

These diagrams should be part of the final version of the functional specification. In an OO-context the DFD could be a sequence diagram.

Regards

Uwe

[Former Member]

Hi Anurag,

<b> GAP Analysis</b>

A through gap analysis will identify the gaps between how the business operates ad its needs against what the package can can't do. For each gap there will be one of three outcomes which must be recorded and actioned, GAP must be closed and customised software can be developed close the gap, GAP must be closed but software cannot be written therefore a workaround is required, GAP does not need to be closed.

In simple terms: Gap means small cracks. In SAP world. In information technology, gap analysis is the study of the differences between two different information systems or applications( ex; existing system or legacy system with Client and new is SAP), often for the purpose of determining how to get from one state to a new state. A gap is sometimes spoken of as "the space between where we are and where we want to be." Gap analysis is undertaken as a means of bridging that space.

Actual gap analysis is time consuming and it plays vital role in blue print stage.

<b>Data Flow Diagrams</b> Data flow diagrams can be used to provide a clear representation of any business function. The technique starts with an overall picture of the business and continues by analyzing each of the functional areas of interest. This analysis can be carried out to precisely the level of detail required. The technique exploits a method called top-down expansion to conduct the analysis in a targeted way.

The result is a series of diagrams that represent the business activities in a way that is clear and easy to communicate. A business model comprises one or more data flow diagrams (also known as business process diagrams). Initially a context diagram is drawn, which is a simple representation of the entire system under investigation. This is followed by a level 1 diagram; which provides an overview of the major functional areas of the business. Don't worry about the symbols at this stage, these are explained shortly. Using the context diagram together with additional information from the area of interest, the level 1 diagram can then be drawn.

The level 1 diagram identifies the major business processes at a high level and any of these processes can then be analyzed further - giving rise to a corresponding level 2 business process diagram. This process of more detailed analysis can then continue – through level 3, 4 and so on. However, most investigations will stop at level 2 and it is very unusual to go beyond a level 3 diagram.

Identifying the existing business processes, using a technique like data flow diagrams, is an essential precursor to business process re-engineering, migration to new technology, or refinement of an existing business process. However, the level of detail required will depend on the type of change being considered.

<b>Entity Relationship Diagrams</b>

http://www.umsl.edu/~sauter/analysis/er/er_intro.html

Cheers

VJ