Reading Response for Lecture 07

Again the readings from this week focus on both the technical and the strategic.

Below is a list of the readings for this class with some suggestions on how to approach them and questions for discussion in class. Please create a post in this discussion consisting of at least 200 words discussing any issue from the required reading for the week (you do not need to address one of the discussion questions below, but you are welcome to do so).  See the Reading Response Grading Rubric for details about how posts will be graded.

The Readings

Larman Chapter 9: Domain Models. Perhaps the best known diagram from UML is the Class Diagram. Larman introduces the class diagram as a way to capture a domain model, which is a representation of the important entities (nouns) in your client's world and the relationship between those entities. In a later reading we will look at how such a domain model can serve as the basis for a Design Class Diagram in which we represent the actual data to be stored in a database along with software classes we will use in our code.

Key objectives in reading this chapter:

1. Learn the basic notation for UML class diagrams.
2. Understand the role that a domain model plays in the design process.

This is a long chapter with lots to take in. Note that much of the chapter consists of Guidelines that help you to tackle some of the specific issues that arise when creating domain models. You may want to skip over some of these guidelines on the first time through this material and return to them when specific issues arise when you go to do your own modeling. Key concepts you want to be sure to understand: classes, attributes, associations, and multiplicities (and how these are represented in UML).

Discussion questions: How does a domain model move us forward in the design process? What is the relationship between a domain model and use cases? In the book Larman introduces System Sequence Diagrams after Domain Models. How do these two diagrams relate to each other? Assuming you will wind up revising both system sequence diagrams and class diagrams going forward, which would you prefer to start with and why? Clearly there is quite a bit of overlap between class diagrams and ER diagrams. What differences (if any) do you see so far?

Severance Chapter 4: Preparing and Implementing Projects. In this chapter we follow GMI into the specific IT priorities and projects that emerge from their strategic planning exercise. One project that might need a bit of explanation is the Y2K remediation work mentioned several times in the chapter. This refers to the Year 2000 problem which captured a big chunk of company budgets in the late 90s: making all necessary changes to existing systems to insure they correctly handled a change in the century and millennium (something that most business systems had not yet had to address). This is a rich chapter that merits a careful reading.

Discussion questions: Given the broad scope of this chapter there are many directions we can go in our class discussion, but here are some ideas to get you started... One issue that shows up in the choice of projects and initiatives is the issue of centralization v. decentralization. What standards did Cunningham impose on the IT architecture and why? Why these priorities? How is GMI dealing with the issue of user resistance? Are the concerns raised by proponents of agile methodologies being anticipated? How?