Registered: Nov 2001
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Posts: 54

True or false. Ideally, all public methods in business model objects are defined directly or indirectly because of a use case requirement.

a) True

b) False

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Registered: Nov 2001
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Posts: 54

If the question said "Ideally, all public methods in *Analysis* model objects are defined directly or indirectly because of a use case requirement", (or *Design* model), it would be a no brainer - true. But this is a smart question, testing our understanding of the business model in the process.

My references are the UML User Guide, UML Reference Manual, and Sams 24 hours. (I also have Gamma... Design Patterns, but not relevant here). None of these seems to clearly define what is actually in the business model, and how it is produced. The right book could probably clarify this immediately.

UML User Guide defines Business Model as "Establishes the abstraction of the organisation".

My books seem to imply that

1. The Business Model is mainly a model of what the business actually does. This is mainly class and interraction diagrams.
2. Use cases define the requirements of the software system.
3. Use cases are developed after the Business Model.

Therefore, business model objects are not derived from Use Cases, and the correct answer for the question is "false".

But, my books also seem to imply

1. Any model (business, Analysis, Deployment ...) can include any UML artifacts

If so, then the Business Model can include Use Cases, which would define what the business does, rather than software requirements. So the correct answer might be "true".

So I have three questions:

1. Can, and should, any model include any UML artifacts?
2. Should the Business Model include Use Cases?
3. If the Business Model includes Use Cases, then do they say what the business does, instead of specifying software requirements?

BTW. I answer true, and I think it was marked correct, so I think the answer to all the above is "Yes"

BTW 2. Why can't I answer this from the UG and RM? Am I missing something, or are they missing something?

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Registered: Nov 2001
Location: Sweden
Posts: 5

Depends on who you ask. Larman and Jacobsson is keen on Use Cases and want everything to derive from them. The hard thing about the process questions on the sample test is that they are general and does not relate to any particular process. If anyone can name a particular process (like Larman, RUP, Objectory, Unified Process etc.) that can give the definitive answer to any question on the sample exam I would be very grateful.

(Only my personal opinion after a few days of preparation.)

Regards,
Torbjorn

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Registered: Apr 2001
Location: New York
Posts: 492

You may find additional discussion for this question on an earlier thread called lead question .

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Registered: Nov 2001
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Posts: 54

I have not been able to find a definition of "Business Model". The closest I can get is:

"One of the UP workflows is Business Modelling; its purpose is to understand and communicate "the structure and the dynamics of the organisation in which a system is to be deployed" [RUP]. A key artifact of the Business Modelling Discipline is the Business Object Model (a superset of the UP Domain Model), which essentially visualises how a business works, using UML class, sequence and activity diagrams." Larmann, p 607.

Consider Larmans NexGen POS system, especially the diagram on p 66. His use cases draw the boundary of the system with the Cashier as a primary actor on the outside of the system. But looking at the enterprise as system, the Cashier is inside the system.

I think that a business object model would have the Cashier as a class, with responsibilities such as Process Sales, Handle Returns, Process Rental. Whoahh! These are the use cases!

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But can anyone find a definition of "Business Model"?

But the business model might also include the Customer. But would the customer be a class? What methods would it have?

I think "True" is looking good.

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Answering my previous questions:

1. Can, and should, any model include any UML artifacts? In general, yes. See Booch... Reference Manual pages 13 -20

2. Should the Business Model include Use Cases?
Probably not, according to above definition from Larman.

3. If the Business Model includes Use Cases, then do they say what the business does, instead of specifying software requirements?

The Business Model doesn't include Use Cases.

An important note from Larman, p 128. "A domain model is illustrated with a set of class diagrams in which no operations are defined". So the domain model has no operations, but the Business Model, being a superset, probably does.

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Registered: Dec 2001
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Posts: 6

Read Larman (P.248) paraphrases:
'Use Cases suggests system events in SSD'

Think of system events as public method in sequece diagrams, which is suggested by use cases.
I think the 'TRUE' is the answer.

Business Model Objects may not be very clear, it can be SSD(sequence diagrams, class diagrams DCD), but it doesn't really matter in this context

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Registered: Nov 2001
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Posts: 16

I assume that business model is a UML artifact called Domain Model, developed in a scope of Business Modeling discipline.
If you look at timing of development of different artifacts (Graig Larman, Applying UML and Patterns, p.77) your will see that Domain Model is not started until Elaboration, but Use Cases already exist by this time and continue to be refined. Some of them might be refined as a result of business modeling, but IDEALY they come first.

Regards,
Sergey

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Registered: May 2002
Location: Raleigh, North Carolina
Posts: 277

Hi,

1. Can, and should, any model include any UML artifacts?
Yes. If it adds value.

2. Should the Business Model include Use Cases?
Yes it does include Use Cases. It is called as Business Use Cases. If you read the Larman's book he gives an example : Serve a Meal in restaurant.

3. If the Business Model includes Use Cases, then do they say what the business does, instead of specifying software requirements?
Yes.

Some highlights from the book UML with Rational Rose 2002 by Wendy Boggs and Michael Boggs.
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UML focuses on a system that will be built, Business modeling instead concentrates on the business around the system.

Business Modeling is the study of an organization. During the business-modeling process, you examine the organization's structure and look at the roles within the company and how they inter-relate. You also examine the organization's workflows, the major processes within the company, how they work, how effective they are, and whether there are any bottlenecks. You will examine the outside entities, whether individuals or other companies, which interact with the business, and look at the implications of that interaction.

In short, you try to understand what is inside and outside the business, and how the inside and ouside talk to each other. In UML, you will document this information in the business model.

To learn more about reasons for doing it, when to do it and so on refer the book.

Cheers,
Bala

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