Verification, Validation, and Testing of Engineered Systems

7.4 THE VVT-TOOL

7.4.1 Background

The VVT-Tool is an experimental database utility created at the IAI in order to maintain system and quality data and implement the quality cost, time and risk models discussed in Chapter 6. Figure 7.8 depicts the VVT modeling tool input and output.

The VVT-Tool is a software package which manipulates and visualizes VVT data (e.g., VVT activities, appraisal risks and impact risks along with their cost, time and other relevant parameters). As depicted in the figure, the VVT-Tool uses a commercial database (Sybase) which receives the VVT strategy and relevant VVT optimization parameters as inputs. The outputs from the VVT-Tool are the expected cost and time and their distribution as well as a list of VVT activities to be performed and a list of potential risks expected to impact the system during its lifetime.

Figure 7.8 VVT modeling tool input and output.

The capabilities of the VVT-Tool are delineated in the Table 7.3.

TABLE 7.3 VVT-Tool Capabilities

Group	Functionalities
General VVT configuration	System lifecycle/VVT configuration Quality cost class Risk probability model 882C Risk cost model System activity VVT activity Appraisal risk	Risk impact Variable constraints Objective function and weights Appraisal risk default Fuzzy α-cut Nonlinear impact Timing scheduler
VVT strategy definition	Probability configuration Fuzzy configuration