A school has a computerised library system that allows students to borrow books for a fixed length of time. The system uses text files to store details of students, books and loans. A new module is to be written which will generate emails to each student who has an overdue book.

1. (a)Decomposition will be used to break down the problem of designing the new module into sub-problems. Identify three program modules that could be used in the design and describe their use. Module 1 Use Module 2 Use Module 3 Use[3]
2. (b)(i)The program designer produces a structure chart for the new module. Part of the structure chart is shown: Module-B() Module-A() Module-C() Module-D() Explain the relationship between the four modules shown.[2]
3. (b)(ii)Two new modules are added: Module-X() and Module-Y(). • Module-X() has no parameters. • Module-Y() will take a string and a real number as parameters and return a Boolean value. • Module-D() will call either Module-X() or Module-Y(). Draw only the part of the structure chart that represents the relationship between Module-X(),Module-Y() and Module-D().[3]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.