Building the Data Warehouse

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A Linear Flow of Deliverables

Except for heuristic processing, a linear flow of deliverables is to be expected. Figure A.11 shows a sample of deliverables that would result from the execution of the process analysis component of the data-driven development methodology.

It is true that within reason there is a linear flow of deliverables; however, the linear flow shown glosses over two important aspects:

METH 11. A linear flow of deliverables for operational process analysis.

■■ The deliverables are usually produced in an iterative fashion.

■■ There are multiple deliverables at any given level. In other words, deliverables at any one level have the capability of spawning multiple deliverables at the next lower level, as shown by Figure A.12.

Figure A.12 shows that a single requirements definition results in three development phases. Each development phase goes through formal requirements definition and into decomposition. From the decomposition, multiple activities are identified, each of which has a dfd created for it. In turn, each dfd creates one or more programs. Ultimately, the programs form the backbone of the completed system.

Figure A.12 METH 12. Deliverables usually spawn multiple deliverables at a lower level.

Estimating Resources Required for Development

Looking at the diagram shown in Figure A.12, it becomes apparent that once the specifics of exactly how many deliverables are being spawned are designed, then an estimation of how many resources the development process will take can be rationally done.

Figure A.13 shows a simple technique, in which each level of deliverables first is defined so that the total number of deliverables is known. Then the time

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