Problem:

Develop three sub-systems namely Staff Profiling System, Inventory Management System and Time-tabling systems.

(a) Show about any three design patterns you have used. Your answer should consist of a brief description of the pattern (including the structure) and a justification for its use and also how these patterns have been re-used. Note: There is no need to give codes to explain your answer but you can include diagrams in your discussion.

(b) What difficulties have you faced when designing and implementing the above mentioned systems using design patterns? A brief discussion will be sufficient.

(c) Suppose that you have been assigned to re-engineer the existing systems for a company. Do you think that design patterns will be applied for these existing systems? Justify your answer.