Types of Prototypes

Prototyping is a visual communication technique used to help the BI project team understand and refine the scope of the project requirements. There are different types of prototypes, each with a different purpose and life expectancy. These prototypes are discussed below in the order of least to most functionality, sophistication, and reusability.

Show-and-Tell Prototype

A show-and-tell prototype serves as a demo for management and business people, as described in Table 6.1. It could also be used to obtain budget approval or to get a business sponsor for the BI application during Step 1, Business Case Assessment.

Table 6.1. Show-and-Tell Prototype

Purposes	Implications
Avoid costly coding by only demonstrating "look and feel." Gain buy-in from business people. Gain business support for the BI application. Secure funding for the BI application.	Business people may mistake the prototype for a functioning system. Be sure to explain that there is no functionality at all ”it is only for visual communication. Concentrate on displaying the most important screens to get business buy-in.

Mock-Up Prototype

The purpose of a mock-up prototype is to understand the access and analysis requirements and the business activities behind them. Therefore, mock-up prototypes are completed in a very short time, as mentioned in Table 6.2. Since the mock-up prototype is just a front for a BI application, it is usually a throwaway .

Table 6.2. Mock-Up Prototype

Purposes	Implications
Understand the application requirements. Understand the business activities. Initiate system functions. Speed is of the essence.	Pay attention to interfaces: building interfaces gives the impression of working code. Use a less sophisticated programming language to build the prototype faster. For example, you may want to use Visual Basic for the prototype and write the final access and analysis application in C++.

Proof-of-Concept Prototype

The purpose of a proof-of-concept prototype is to explore implementation uncertainties. This method allows the identification of risks and unknowns, thereby enabling the decision whether or not to proceed with the project, as indicated in Table 6.3.

Table 6.3. Proof-of-Concept Prototype

Purpose	Implications
Explore implementation risks and unknowns to decide whether or not to proceed.	Stay narrow in scope. Do not build any application interfaces. Build only enough functionality to make a go/no-go decision.

Visual-Design Prototype

A visual-design prototype is a step up from a mock-up. It is ideal for developing interface specifications for the access and analysis portion of the BI application. Good interface specifications are mandatory, as listed in Table 6.4. Visually, it is important for business people to have as much information as possible on the same screen to avoid toggling between screens. Once the code is generated, this type of prototype may survive and be incorporated into the final BI application. Therefore, unless you are certain that this prototype is a throwaway, stay away from "quick and dirty" code. There is no such thing as a one-time-use-only program. Once a program works, even if it does not work well, it is liable to be used forever.

Table 6.4. Visual-Design Prototype

Purposes	Implications
Understand the design of visual interfaces. Develop specifications for visual interfaces and displays.	If the intent is to use the prototype like a mock-up only, write it in a language different from the delivery language so you can complete it faster. If the intent is to potentially use the prototype for the final BI application, write it in the delivery language from the start so you can reuse it for the real BI application. Allocate additional time for writing quality code.

Demo Prototype

A demo prototype is used to convey vision and partial functionality to business people, business managers, potential customers, or other external groups, as indicated in Table 6.5. It is not fully functioning, but it is more sophisticated than code stubs.

Table 6.5. Demo Prototype

Purposes	Implications
Convey the vision of the BI application to the business people or to external groups. Test the market for the viability of a full-scale BI application. Test or demonstrate the usability of the proposed access and analysis portion of the BI application.	On the initial screen, graphically convey what percentage of the application is represented by the prototype so you set realistic expectations. Otherwise, the business people may mistake this prototype for a functioning application.

Operational Prototype

An operational prototype is the most involved, most extensive , and most time-consuming of all prototypes. As a result, it is also the most expensive, most complete, most functional, and most likely to survive and evolve into the real access and analysis portion of the BI application. The purpose of this prototype is to obtain feedback from the business people who participate in the prototyping activities through the actual use of the application's functionality. This is accomplished by designing the entire access and analysis application up front but using only a basic part of the code to generate the prototype. It can be considered a bare-bones application, with just enough functionality to evoke feedback, as mentioned in Table 6.6. This type of prototype is also excellent for hands-on training.

Table 6.6. Operational Prototype

Purposes	Implications
Create an almost fully functioning pilot for alpha or beta use of the access and analysis portion of the BI application. Obtain feedback through real hands-on trials of the bare-bones application.	On the initial screen, graphically convey what percentage of the application is represented by the prototype so you can set realistic expectations. This prototype has a high potential for evolving into the final access and analysis portion of the BI application. Write the prototype in the delivery language. Allocate additional time for writing quality code.