Titlebook: SSADM in Practice; A Version 4 Text Joyce Duncan,Lesley Rackley,Alexandria Walker Textbook 1995Latest edition J. Duncan, L. Rackley and A.

切碎

gerrymander

,Step 340 — Enhance Required Logical Data Model,M works from the top down, taking an overview of the data model and gradually adding more information, while RDA works from the bottom up, starting with arbitrary data groups and forming larger groups that correspond to the entities and relationships of the LDM.

META

cushion

Habituate

夸張

,Stage 3 — Requirements Specification,oad approach to be adopted for the new system. Having defined what the new system is intended to achieve in outline, we can now move into Stage 3 and start to specify the requirements in more detail. The steps and products of Stage 3 are shown in Figure 5.1.

使饑餓

前兆

Stage 3: Develop Processing Specification,modelling technique is used to enable the analyst to acquire a more detailed understanding of the system. Entity-event modelling leads to further explorations of how the system works and completes the Logical Data Model, providing a specification of database update processing via the effect correspo

繁忙

PRO