Problem 1
Explain why it may be necessary to design the system architecture before the specifications are written.
Problem 2
Explain why design conflicts might arise when designing an architecture where availability and security requirements are the most important functional requirements.
Problem 4
Giving reasons for your answer, suggest an appropriate structural model for the following systems: An automated ticket-issuing system used by passengers at a railway station A computer-controlled video conferencing system that allows video, audio and computer data to be visible to several participants at the same time A robot floor-cleaner that is intended to clean relatively clear spaces such as corridors. The cleaner must be able to sense walls and other obstructions.
Problem 6
Real-time systems usually use event-driven models of control. Under what circumstances would you recommend the use of a call-return control model for a real-time system?
Problem 7
Giving reasons for your answer, suggest an appropriate control model for the following systems: A batch processing system that takes information about hours worked and pay rates and prints salary slips and bank credit transfer information A set of software tools that are produced by different vendors, but which must work together A television controller that responds to signals from a remote control unit.
Problem 8
Discuss their advantages and disadvantages as far as distributability is concerned of the data-flow model and the object model. Assume that both single machine and distributed versions of an application are required.
Problem 10
Should there be a separate profession of 'software architect' whose role is to work independently with a customer to design a software system architecture? This system would then be implemented by some software company. What might be the difficulties of establishing such a profession?
