TFH Berlin Fachbereich Informatik Medieninformatik SA31: Systemanalyse / SWT1: Softwaretechnik 1 Wintersemester 2000/2001

Lab 1 : Getting started

Lots of writing to do today! Consider the following questions. Write your answers as a home page and send me the URL. You may work in groups of two.

1. What is the purpose of modelling?

 
2. What is meant by "knowledge acquisition is nonlinear"? Provide a concrete example of knowledge acquisition that illustrates this.

 
3. Hypothesize a rationale for the following design decisions:
• "The ticket distributor will be at most one and a half meters tall."
• "The ticket distributor will include two redundant computer systems."
• "The ticket distributor will include a touch screen for displaying instructions and inputing commands. The only other control will be a cancel button for aborting a transaction."

 
4. Specify which of the following statements are functional requirements and which are nonfunctional requirements:
• "The ticket distributor must enable a traveler to buy weekly passes."
• "The ticket distributor must be written in Java."
• "The ticket distributor must be easy to use."

 
5. Specify which of the following decisions were made during requirements or system design:
• "The ticket distributor is composed of a user interface subsystem, a subsystem for computing tariff, and a network subsystem managing communication with the central computer."
• "The ticket distributor will use PowerPC processor chips."
• "The ticket distributor provides the traveler with an on-line help."
6. A passenger aircraft is composed of several millions of individual parts and requires thousands of persons to assemble. A four-lane highway bridge is another example of complexity. The first version of Word for Windows, a word processor released by Microsoft in November 1989, required 55 person-years, resulted into 249,000 lines of source code, and was delivered 4 years late. Aircraft and highway bridges are usually delivered on time and below budget, whereas software is often not. Discuss what are, in your opinion, the differences between developing an aircraft, a bridge, and a word processor, which would cause this situation.

7. You've implemented a coffee machine, now we are going to look at a ticket distributing machine. Make a list of all the things you think a ticket distributing machine is supposed to do!