Chapter 10 Review Questions

1. System architecture is the conceptual model that defines the structure and/or behavior of a system. It translates the logical design of an information system into a physical structure that includes hardware, software, network support, processing methods, and security. Scalability is a system’s ability to expand, change, or downsize easily to meet the changing needs of a business enterprise. Scalability is especially important in implementing systems that are volume-related, such as transaction processing systems.

2. Before selecting the system architecture, the analyst must consider the following issues:
Enterprise resource planning (ERP)
Initial cost and (TCO)
Scalability
Web integration
Legacy system interface requirements
Processing options
Security issues

3. Enterprise resource planning (ERP) defines a specific architecture, including standards for data, processing, network, and user interface design. It is important because it describes a specific hardware and software environment that ensures hardware connectivity and easy integration of future applications, including in-house software and commercial packages. ERP also can extend to suppliers and customers in a process called supply chain management. In a totally integrated supply chain, a customer order could cause a production planning system to schedule a work order, which in turn triggers a call for certain parts from one or more suppliers.

4. A server is a computer that supplies data, processing services, or other support to one or more computers, called clients. An example of server-based processing is the creation & adaptation of a database using MySQL.

5. Client/Server Architecture refers to systems that divide processing between one or more networked clients and a central server. The client submits a request for information from the server, which carries out the operation and responds to the client. Early client/server systems did not produce expected cost savings. As large scale networks grew, client server systems became more cost effective.
Client/Server architecture can use two types of clients: fat and thin. A fat/thick client design locates all or most of the application processing logic at the client. A thin client design locates all or most of the processing logic at the server. Thin client design provides better performance and a lower TCO. Fat client design is simpler and less expensive to develop.
Client/Server can implement two different tier designs: Two-tier and Three-tier design. In a two-tier design, user interface resides on the client, all data resides on the server and application logic can run on either. In a three-tier design the user interface and data aspects are the same as a two-tier but, an application server processes the client requests and translates them into data access commands. Also they enhance the overall performance by reducing the server’s workload and relieve clients of complex processing tasks.
Middleware is the software that connects dissimilar applications and enables them to communicate and exchange data.

6. The internet has had a major impact on system architecture in the sense that, the internet has become more than a communication channel, as many IT observers see it as a fundamentally different environment for system development. Examples include e-commerce and corporate portals.

7. Online processing is a system that handles transactions when and where they occur and provides the user output directly. An airline reservation system is a good example. With a batch processing system the data is collected and processed in groups, or batches as the name states. An example of such a system would be the compilation of a firm’s customer statements at the end of the month.

8. LAN is a network that allows sharing of data and hardware resources from a local server that supports a group of users or a department. WAN is a network that spans long distances and can connect LANs that are continents apart. Topology refers to a physical or a logical view of the network.