Purposes of Prototyping


Prototyping can be an effective method for validating the project requirements and finding missing pieces and discrepancies in the requirements. Business people seldom think of all the details when they state their requirements. They often forget to include dependent processes or related data. A prototype can also help them focus on their access path requirements because they will see the capabilities of the BI technology and the access and analysis portion of their BI application.

If time and budget permit, building a prototype for the original requirements allows the business community to test, extend, or change those requirements at an early stage when the impact on the project schedule is not yet high. The costs of experimenting with different database designs, different visualization methods , different development tools, or different application programming techniques are much less during prototyping than during development because they do not affect a full-scale application.

Another purpose for prototyping is to verify that the design as well as the selected tools, database management system (DBMS), and other technology components will be appropriate for the BI decision-support environment. If the functions of all technology components perform as expected during the prototype development, then the chances of having a successful BI implementation are increased. Therefore, testing the technology features is a valuable benefit of prototyping, regardless of whether you are using existing technology components or buying new ones.

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Testing the technology for performance, however, is usually not a valid purpose for a prototype. A prototype is not a stress-test environment. It is usually loaded with only small sets of data, and its main purpose is to try out visual interfaces and functionality.

Time-Boxing

Everyone likes prototyping. It is fun and creative, dynamic and exciting ”and it is meant to be short. Thus, a word of caution: It is tempting to endlessly expand the scope of the prototype. Prolonging the prototyping effort beyond its original purpose reduces the cost-effectiveness of the prototype and produces diminishing returns, as shown in Figure 6.1. It also reduces control over the project as the prototype starts to feel like a runaway train.

Figure 6.1. Uncontrolled Prototyping Activity

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Each prototype iteration should be limited in duration to just a few weeks, and the activities within each prototype iteration should be time-boxed for every week, as illustrated in Figure 6.2. Prototyping activities are carefully planned and monitored . Each participant must know which tasks to perform and which task deliverables to produce by the end of every week.

Figure 6.2. Controlled (Time-Boxed) Prototyping Activity

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As unexpected discoveries arise (one main reason for prototyping is to find out what does not work), the plan should be revised for every team member who is affected by that discovery. The plan and schedule for the prototype can be extended or shortened . A plan does not dictate what must be done; it is only a proposal for activities that make the most sense at the time. If something does not make sense anymore, change it.



Business Intelligence Roadmap
Business Intelligence Roadmap: The Complete Project Lifecycle for Decision-Support Applications
ISBN: 0201784203
EAN: 2147483647
Year: 2003
Pages: 202

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