Foundations of Modern Systems Design


Notebook Computer Servicing Pte Ltd owns four notebook servicing centers. A notebook serviced by a service center belongs either to an individual or a corporate body registered with the service center. Each service center employs several technicians to carry out the servicing.

Notebook Computer Servicing requires a system to support its administrative functions as follows:

  • Given the location of a service center, the system will provide the name, contact number and qualifications of each technician currently employed by the service center.
  • During peak seasons, the company employs part-time technicians to assist the full-time technicians and these part-time technicians are paid on an hourly rate and the system needs to keep track of the number of hours worked.
  • In response to an enquiry on corporate customers, the system will, for each service center, provide a list containing the business name and email address of each company registered with that service center. For each such company, the system will list the brand, model and serial numbers of all notebooks serviced by the service center.
  • Given the location of a service center, and the service number of a servicing that it had carried out, the system will provide the date of the servicing and the serial number of the notebook that was serviced. If the notebook is owned by an individual, the system will provide the name and phone number of that person; otherwise, it will provide the name of the company that owns the notebook. For a major servicing, the system will also provide details of the parts changed in the servicing, and the name of all technicians who participated in that servicing.


Analyze the above case description, and answer the following questions:

  • Identify the classes, and their respective attributes, from the above description, using the tabular format in Table Q1(a) below:










b) Identify the class hierarchy or hierarchies among the classes, naming each class appropriately. Discuss why there should be such a hierarchy or hierarchies with reference to the case description.


(c) Explain whether there should be any abstract class(es) in the class hierarchies or hierarchies in (b) above.

 (d) Draw a UML diagram(s) to depict the class hierarchy or hierarchies. Show the attributes (including their respective visibilities and data types) for each class. You need not include the methods.

(e) Write Java code to implement the Customer class. Include the instance variables, constructors (with necessary parameters), the setter and getter methods, and the toString() method.

 (f) Notebook Computer Servicing Pte Ltd offers a discount of 10% and 20% to individual and corporate customers respectively.

(i) Explain how this could be provided in the system.

(ii) Write Java code in the classes concerned to implement this.


Summary: This question belongs to modern systems design and discusses about a serving company’s operations and hierarchies among the classes.

Total word count: 520


Download Full Solution


  • HWA

    this is a very good website

  • HWA

    I have 50 questions for the same test your page is showing only 28

  • HWA

    hi can you please help or guide me to answer my assignments. thanks

  • HWA

    hi can anyone help or guide me to my assignments. thanks

  • HWA

  • HWA

    This solution is perfect ...thanks

  • HWA

    Hello Allison,I love the 2nd image that you did! I also, had never heard of SumoPaint, is something that I will have to exolpre a bit! I understand completely the 52 (or so) youtube videos that you probably watched. Sometimes they have what you want, sometimes they don't! However, it is always satisfying when you are able to produce something that you have taught yourself. Great job!Debra 0 likes

  • HWA

    Perfect bank of solution. 

  • HWA

    great !

  • HWA
    Paul Brandon-Fritzius

    thanks for the quick response. the solution looks good. :)

  • HWA
    tina Johnson

    thnx for the answer. it was perfect. just the way i wanted it. 

  • HWA

    works fine.