None of the forms hint at a ClientID. A numeric ClientID serves better. Each Configuration is associated with a particular Client. The following tables contain the attributes identified from each form and the interview. Another alternative is to start with this data model for Milestone 5 but add additional requirements, such as the Milestone 4 Advanced Option and require that students revise the data model accordingly.
If you will be doing Milestone 5 as a separate assignment, you may want to withhold this solution. Each EquipmentComponent is a particular ComponentType. Activity 3 — Event Diagrams hese diagrams represent one possible implementation of the ten events in the EventResponse List Exhibit 6. None of the forms hint at a ClientID. This would also be a system-generated number.
Case study CTTS milestone 06 process modeling
As a number it would also consume less disk space as a foreign key in related tables and would provide for faster joins. Would you track accounts payable?
An EquipNum is solutkon number that could be generated by the system and stays unchanged forever. The Enter New Client event could be placed in either subsystem; presumably the two subsystems will share data so that a client entered in one will be available in the other.
A request for service on Equipment. This would also be a system-generated number.
Foreign keys are marked with FK and a number. Family Vacation Rentals Tcts Name i. Work done to resolve a SeviceRequest. Each piece of Equipment is a particular EquipmentType.
Milestone 06 参考答案_图文_百度文库
Another alternative is to start with this data model for Milestone 5 but add additional requirements, such as the Milestone 4 Advanced Option and require that students revise the data model accordingly. Optional Entities A classification of Equipment. The EquipmentComponent entity has ComponentNum as the primary key.
But a long text field such as the client name would make a poor primary key for Client, consuming extra storage space, slowing down database operations, and probably requiring extra typing.
Make sure students specify primary keys that uniquely identify the entities as well as use proper names for the keys. Subject to interpretation, this diagram is in third normal form, which is the bulk of the assignment for Milestone 5.
Vendor would be a parent table to PurchaseOrder, contributing the VendorID in a non-identifying relationship. A Client submits one or more ServiceRequests, ctrs may related to a piece of Equipment. Each Configuration is associated with a particular Client.
Because this does not apply to all records, a formal relationship would not have to be established. But make sure each non-key attribute exists in only one entity. Whether or not they identify the optional entities will depend on how they interpret the user requirements and on their experience level with database normalization. Students should realize that the Parent-Child relationship found in PurchaseOrder and PurchaseOrderDetail will be present in any invoicing system and many other systems as well.
However, Jeff Summers states that the computer name is sometimes changed. Would you also have payments? Each ServiceRequest will be worked on with zero or more WorkRecords initially zero but eventually at least one.
The following diagram illustrates one possible solution. In most activities explanations for why things were done as they were have been provided to aid in your understanding of the solution. The real problem with adding purchase orders to CTTS is that it opens the door on accounting functions.
Some, but not all, of the configuration records could be associated with a piece of Equipment. The diagram below includes foreign keys, assuming implementation in a relational database.
Activity 3 — Event Diagrams hese diagrams represent one possible implementation of the ten events in the EventResponse List Exhibit 6.
The Equipment entity has EquipNum as the primary key. Also remember that data flows are not allowed between entities. Each piece of Equipment is owned by a particular Client.