ISBN : 978-81-963532-2-3 (E-Book) Fig 10.2 (a) Level 0 (b) Level 1 DFD for Tic-Tac-Toe game It may be recalled that the DFD model of a system typically consists of several DFDs: level 0, level 1, etc. However, a single data dictionary should capture all the data appearing in all the DFDs constituting the model. Figure 10.2 represents the level 0 and level 1 DFDs for the tic-tac- toe game. The data dictionary for the model is given below. Data Dictionary for the DFD model in Example 1 move: integer /*number between 1 and 9 */ display: game+result game: board board: {integer}9 result: [“computer won”, “human won” “draw”] It may be recalled that the DFD model of a system typically consists of several DFDs: level 0, level 1, etc. However, a single data dictionary should capture all the data appearing in all the DFDs constituting the model. Figure 10.2 represents the level 0 and level 1 DFDs for the tic-tac- toe game. The data dictionary for the model is given below. Data Dictionary for the DFD model in Example 1 move: integer /*number between 1 and 9 */ display: game+result game: board board: {integer}9 result: [“computer won”, “human won” “draw”] Importance of Data Dictionary A data dictionary plays a very important role in any software development process because of the following reasons: • A data dictionary provides a standard terminology for all relevant data for use by the engineers working in a project. A consistent vocabulary for data items is very important, since in large projects different engineers of the project have a tendency to use different terms to refer to the same data, which unnecessary causes confusion. • The data dictionary provides the analyst with a means to determine the definition of different data structures in terms of their component elements. 47 Software Engineering Keerthana P, Manasa KN, Ganga D Bengal
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