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Chapter 4 -- Exercises

A. Investigate the Web site for Rational Software (www.rational.com) and its
repository of information about UML. Write a paragraph news brief on the current

state of UML (e.g.,

improvements; the current version and when it will be released; future
etc.).

Rational software is based on the theory and structure of UML, however UML is simply
a tool to document system design. Rational goes another step and allows the user to
design software with additional business designs and components, as well as facilitates
communication and organization of the project. These additional functions create an
effective tool for enterprise level application.
The Unified Modeling Language™ (UML™) is the industry-standard language
for specifying, visualizing, constructing, and documenting the artifacts of software
systems. It simplifies the complex process of software design, making a "blueprint" for

construction.
UML for databaseFor database professionals
design allows UMLand
the business canapplication
be used forteams
database
whodesign. Using the
are already
using the UML for their designs to share a common language and to communicate with
the database team.
The Unified Modeling Language (UML) is a widely used standard in the software
industry for modeling software. It helps practitioners visualize, communicate, and
implement their designs. UML 2.0 is the first major revision to the standard since its
inception in 1997. The new specification is designed to support a number of model-
driven development paradigms, including Model-Driven Architecture (MDA) as defined
 by the Object Management Group (OMG). The UML is an integral component of IBM's
ongoing commitment to supporting open standards in the software industry.
Latest news according the Rational website, although very technical for someone
new to UML.
On November 18, 2003, IBM initiated a new open source project within
Eclipse.org, focusing on implementing a metamodel and a set of APIs for UML 2.0. This
 project, which is an Eclipse Tools sub-project, is an EMF-based implementation of the
UML 2.0 metamodel for the Eclipse platform.
The objectives of this project are to provide a useable implementation of the
metamodel to support the development of modeling tools, a common XMI schema to
facilitate interchange of semantic models, test cases as a means of validating the
specification, and validation rules as a means of defining and enforcing levels of
compliance.

B. Investigate the Object Management Group. Write a brief memo describing what
it is, its purpose, and its influence on UML and the object approach to systems
development. (H i n t: A good resource is www.omg.org.)

OMG’s MDA (Model Driven Architecture) aims to build industry standards for design
architecture that will utilize existing architecture, and allow effective future expansion.
MDA is based on the concept of modeling with UML. At the heart of MDA is an

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approach to design based on treating it as a product, rather than a process. Non-MDA

approaches treat design as a process in which developers apply their expertise to
handcraft elegant solutions from often ill-defined problems. The result is running code.
The design is not captured explicitly, but instead smeared across the code as a set of
results of a skilled thinking process.

Mellor,In anothers,
and MDA theapproach,
design promulgated by OMG
is itself a product and
that is based onasthe
expressed work
a set of of Shlaer and
formal
mapping rules. Examples of such rules are "Turn an application class into a class in the
implementation with a container for its instances" and "Turn each transition on a
statechart diagram into a tuple in a linked list defining the transition and the procedure to
call to execute actions". These rules are the design, and once they are executed against an
application model that captures a problem, the result is (more or less) running code.
In MDA the application model is generalized as a platform-independent model1,
or PIM, usually visualized using standard UML, and the framework for formal
transformation rules is currently being standardized as the QVT (Query, Views, and
Transforms) specification. The result of the transformation can either be another,

 platform-specific,
database schemas,model (PSM),
deployment or components
scripts, of or
test scripts, theindeed
target executable
application,code.
such In
as the latter
case, the PIM must be behaviorally complete, defining business logic in terms of abstract
actions.
With its rich palette and middleware independence, UML forms the foundation of
OMG's Model Driven Architecture (MDA). In fact, a UML model can be either platform-
independent or platform-specific, as we choose, and the MDA development process uses
 both of these forms: Every MDA standard or application is based, normatively, on a
 Platform-Independent Model  (PIM), which represents its business functionality and
 behavior very precisely but does not include technical aspects. From the PIM, MDA-
enabled development tools follow OMG-standardized mappings to produce one or more
 Platform-Specific Models (PSMs), also in UML, one for each target platform that the
developer chooses. (This conversion step is highly automated, but not magic: Before the
tool produces a PSM, the developer must annotate the base PIM to produce a more
specific but still platform-independent PIM that includes details of desired semantics, and
guides choices that the tool will have to make. Because of the similarities among
middleware platforms of a given genre - component-based, or messaging-based, for
example - this guidance can be included in a PIM without rendering it platform-specific.
Still, developers will have to fine-tune the produced PSMs to some extent, more in early
days of MDA but less and less as tools and algorithms advance.)

C. Draw a use-case diagram and a set of activity diagrams for the process of buying
glasses from the viewpoint of the patient. The first step is to see an eye doctor who
will give you a prescription. Once you have a prescription, you go to a optical
dispensary, where you select your frames and place the order for your glasses. Once
the glasses have been made, you return to the store for a fitting and pay for the
glasses.

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D. Create a set of detail use-case descriptions for the process of buying glasses in
Exercise C.

1.  The system boundary statement should include all steps involved in
determining the need through final payment for eyeglasses. Excluded would
 be any diagnosis or prescription from the doctor for other eye related
 problems; excluded would be all issues pertaining to driving, flying, walking,
or taking a taxi to the store; excluded would be any calls to see if the glasses
are ready or visits prior to the glasses being ready; purchase of other
equipment such as an eyeglass case; and issues of checks bouncing or credit
cards being overcharged. Individual students may see differently what exactly
is included and what is excluded. The key, though, is identifying some items
that are not to be included in the system. It will be interesting to see how
many in the class believe that the going to the doctor, going to the store, and
returning to the store are inside versus outside the boundary of the system.
This would represent a good in class discussion opportunity focusing on why
you might include or exclude these.

2.  The primary actors include the purchaser, the doctor, the eyeglass store
employees. The instructor will have to judge any others that the student might
identify (e.g. the subcontractor who receives the prescription and grinds the
lenses) and consider whether these actors are inside or outside of the boundary
of the system.

3.  Each of the main steps should generate one or more goals. The prescription
should be accurate; the frames should be compatible with the lenses, should
 be affordable and within the appropriate style range as viewed by the
customer; the fitting should assure that all elements of the glasses are
appropriate; the payment should conclude the transaction such that the store
receives appropriate funds and the customer receives the glasses and a receipt.

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F. Create a set of detail use-case descriptions for the dentist office system in Exercise
E.

1.  It may be challenging to delineate the boundary. Note that managing the
dental office staff or advertising for new customers should clearly be outside
this system.

2.  The problem identifies this as a dental office system. However, the actions
are better described as a scheduling or medical records system. Actors should
include the prospective patient, the patient (a subset of prospective patients),
office staff, and, perhaps, the dentist.

3.  Each step should trigger one or more goals. The new appointment must not
conflict with earlier scheduled appointments (other metrics will vary by

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office), collecting information should result in a complete and accurate record,

the mailed appointment should occur within the parameters listed and should
result in decrease in missed appointments.

4.  Students should identify the following high level tasks:

  See new patients

o  Schedule new appointment

o  Collect full patient information

o  Mail appointment reminder

 Note that the rest of the contingencies and conditions should be viewed as
expansions of these basic activities. Also note that the steps are not
 presented in typical logical sequence in the problem –  gathering patient
information is presented first, but will be conducted after the new
appointment is scheduled.

G. Draw a use-case diagram and a set of activity diagrams for an online university
registration system. The system should enable the staff of each academic
department to examine the courses offered by their department, add and remove
courses, and change the information about them (e.g., the maximum number of
students permitted). It should permit students to examine currently available
courses, add and drop courses to and from their schedules, and examine the courses
for which they are enrolled. Department staff should be able to print a variety of
reports about the courses and the students enrolled in them. The system should
ensure that no student takes too many courses and that students who have any

unpaid fees are not

the university’s permitted
financial towhich
office, register
the(assume that fees
registration dataaccesses
system are maintained
but does by
not
change).

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H. Create a set of detail use-case descriptions for the online university registration
system in Exercise G.

 Note also that the functionality available to department staff is listed in two separate
sections –  items 1-3 then later items 4-5.

Department Staff

1. Examine departmental courses

2. Add and remove courses

3. Change information about courses

Assuming a database with a table for courses, the first three activities should
involve selecting courses by department of the information requestor. The first

function would relate

much information to a “list”
to display command
(numbers innumbers
only, SQL or aand related
titles,language.
numbers,How
titles,
and full descriptions) may be pre-specified or left for run-time menu options for
the user. A blank, possibly pre-formatted screen should be available to accept
new course information; matching by course name or number should bring a
current course for deleting (removing) or for revising and re-storing.

4. Print reports about courses

5. Print reports about students enrolled in courses

Assuming a database with tables for courses, students, and enrollments, these
reports should be designed to appropriately merge tables and allow for user
specification of additional selection criteria for students/courses or for full output
of all details.
Students may answer this question in terms of step-by-step what the
department user must do in order to achieve these tasks without reference to the
database functionality embedded in the application.
Instructors may want to select this exercise if the preponderance of
students have already taken a database course. Alternatively, this will be a
challenging exercise for students who have not taken a database course, but can
 be a good precursor to membership in such a course.

Students

1. Examine currently offered courses

This should draw information from an “offered courses” table. Exceptions should

 be noted in terms of things like courses offered but not available to a given
student (e.g. only for those in a different major thus needing petitioning for entry;

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those that are already fully enrolled; those that are for different student levels such
as for seniors only; etc.)

2.  Add and drop courses from their schedule

  
ensure that no student takes too many courses
   ensure that students may not register if they have unpaid fees

This should enable students to add or delete records from the “enrollment” table.
Data regarding their identifier, the identifier of the course, and any other
“enrollment” data should be added to the record. It should also add one student to
the “courses offered” table’s enrollment counter.
This task will also require utilization of application business logic for
integrity constraints. Too many course restrictions will require determining the
 proper upper limit of courses or units the student is allowed to take (as this will
vary based on different business rules –  GPA, probation, major, etc.) then

comparing this with

requested course the prior
is added. Thenumber
unpaidcommitted to andwill
fees restriction the require
new total if the the
matching
student id with the identifier in the financial office database and returning an OK
flag or a set of values pertaining to the unpaid fee indication.

3. Examine courses in which they are enrolled

This task will involve providing a listing of the course information from the
course table that matches those listed for the student in the “enrollment” table.

I.
A Draw a use-case
Real Estate diagramsells
Inc. (AREI) andhouses.
a set ofPeople
activitywho
diagrams
want tofor the
sell following
their housessystem.
sign a
contract with AREI and provide information on their house. This information is
kept in a database by AREI and a subset of this information is sent to the citywide
multiple listing service used by all real estate agents. AREI works with two types of
potential buyers. Some buyers have an interest in one specific house. In this case,
AREI prints information from its database, which the real estate agent uses to help
show the house to the buyer (a process beyond the scope of the system to be
modeled).Other buyers seek AREI’s advice in finding a house that meets their
needs. In this case, the buyer completes a buyer information form that is entered
into a buyer data base, and AREI real estate agents use its information to search

AREI’s dataofbase
The results and
these the multiple
searches listingand
are printed service
usedfor houses
to help thethat
realmeet their needs.
estate agent show
houses to the buyer.

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J. Create a set of detail use-case descriptions for the real estate system in Exercise J.

Major use cases are listed by actor:

Sellers

1. Sign contract

Possible expansion steps include: present contract, discuss key items, negotiate
any specifics such as percentage commission, finalize contract contents, seller
signs contract, AREI employee signs contract, perhaps a witness also signs, dates
are included, the contract is filed (how would this differ if on-line?)

2. Provide information regarding house

Students may list some of the specific details regarding the house. Will the
information be written on paper then entered later by data entry specialists, or
entered directly onto a computer screen?

AREI

1. Add information to database

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This may be a separate step, if data is gathered manually, or it could be an

example of a use-case activity with multiple actors.

2. Extract subset and send to multiple listing service.

The
will subset is assumed
be included in the to be constant
extraction amongIshouses,
program. therefore
the data printed the
andselection
sent on orlogic
is it
sent by email or other electronic means?

3. Print specific house information (for showing to buyer)

Use house identifier to locate all data in database pertaining to a particular house,
 print the data, and share with buyer/buyer agent.

4. Service general buyer process -- note this sequence is complex enough to possibly
warrant a separate lower level use case.

4A. Adds buyer information form to database

Aame issues as with adding seller information

4b. Search AREI database for buyer desire/specific house match

Discuss preferences with client, formulate selection values, enter selection

values, and extract data subset. The assumption is that this will be
displayed on-screen prior to printing in step 4d.

Students may make the other assumption, that printing results directly
following the extraction. There would be advantages to reviewing the
displayed results to delete those not appropriate and, potentially, to
redefine the search values before printing the hard copy.

4c. Search multiple listing database for buyer desire/specific house

match

Same issues as 4b with the additional complexities of looping through a

set of databases if these have not been unified and the various protocols
and methods this might theoretically entail.

4d. Print AREI database search results

 print the results, retrieve from printer, discuss with client

4e. Print multiple listing database search results.

 print the results, retrieve from printer, discuss with client

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Buyer

1. Completes buyer information form issues similar to seller step 2.

K. Perform a verification and validation walkthrough of the functional models of

the real estate system described in exercises I and J.

In order to verify and validate the functional model, a set of rules have been defined to
ensure the consistency among the activity diagram (described in I), the use-case
description (described in J), and the use-case diagram (defined in I).

First, when comparing an activity diagram to a use-case description, there should be at

least one event recorded in the normal flow of events, subflows, or alternate/exceptional
flows of the use-case description for each activity or action that is included on an activity
diagram, and each event should be associated with an activity or action.

Second, all in
in an event objects portrayed
the normal flowasofan objectsubflows,
events, node in anoractivity diagram must flows
alternate/exceptional be mentioned
of the
use-case description.

Third, sequential order of the events in a use-case description should occur in the same
sequential order of the activities contained in an activity diagram.

Fourth, when comparing a use-case description to a use-case diagram, there must be one
and only one use-case description for each use case, and vice versa.

Fifth, all actors listed in a use case description must be portrayed on the use-case
diagram. Furthermore, each one must have an association link that connects it to the use
case and must be listed with the association relationships in the use-case description. In
some organizations, we should also include the stakeholders listed in the use-case
description as actors in the use-case diagram.

Sixth, all other relationships listed in a use-case description (include, extend, and
generalization) must be portrayed on a use-case diagram.

Finally, there are many diagram-specific requirements that must be enforced. For
example, in an activity diagram a decision node can be connected to activity or action
nodes only with a control flow, and for every decision node there should be a matching
merge node. Every type of node and flow has different restrictions.

L. Draw a use-case diagram and create a set of activity diagrams for the following
system. A Video Store (AVS) runs a series of fairly standard video stores. Before a
video can be put on the shelf, it must be cataloged and entered into the video
database. Every customer must have a valid AVS customer card in order to rent a

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video. Customers rent videos for three days at a time. Every time a customer rents a
video, the system must ensure that they do not have any overdue videos. If so, the
overdue videos must be returned and an overdue fee paid before customer can rent
more videos. Likewise, if the customer has returned overdue videos, but has not
paid the overdue fee, the fee must be paid before new videos can be rented. Every

morning, thedays
two or more storeoverdue,
managertheprints a report
manager that
calls thelists overdue
customer to videos.
remindIf a video
them is
to return
the video. If a video is returned in damaged condition, the manager removes it from
the video database and may sometimes charge the customer.

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M. Create a set of detail use-case descriptions for the video system in Exercise L.

Major use cases are listed by actor:

Video store staff

  Catalogue video
  Enter video into database
  Put video on shelf

Customer

  Obtain an account
  Rent a video

  Check for overdue videos
o  Receive overdue video

o  Receive overdue video fine

Store manager
  Print overdue video list (daily)


o  Sort overdue video records/items by length of time overdue

o  Print list

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  Call overdue video clients (two or more days late)

  Deal with damaged video
o  Inspect videos upon return

o  Remove damaged videos from database

o  Prepare customer damage charges (rules not specified)

N. Perform a verification and validation walkthrough of the functional models of

the video store system described in exercises L and M.

In order to verify and validate the functional model, a set of rules have been defined to
ensure the consistency among the activity diagram (described in L), the use-case
description (described in M), and the use-case diagram (defined in L).

First, when comparing an activity diagram to a use-case description, there should be at

least one event recorded in the normal flow of events, subflows, or alternate/exceptional

flows of the
diagram, anduse-case description
each event should befor each activity
associated withoranaction that
activity orisaction.
included on an activity

Second, all objects portrayed as an object node in an activity diagram must be mentioned
in an event in the normal flow of events, subflows, or alternate/exceptional flows of the
use-case description.

Third, sequential order of the events in a use-case description should occur in the same
sequential order of the activities contained in an activity diagram.

Fourth, when comparing a use-case description to a use-case diagram, there must be one

and only one use-case description for each use case, and vice versa.
Fifth, all actors listed in a use case description must be portrayed on the use-case
diagram. Furthermore, each one must have an association link that connects it to the use
case and must be listed with the association relationships in the use-case description. In
some organizations, we should also include the stakeholders listed in the use-case
description as actors in the use-case diagram.

Sixth, all other relationships listed in a use-case description (include, extend, and
generalization) must be portrayed on a use-case diagram.

Finally, there
example, in anare many diagram
activity diagram-specific
a decisionrequirements
node can bethat must betoenforced.
connected For
activity or action
nodes only with a control flow, and for every decision node there should be a matching
merge node. Every type of node and flow has different restrictions.

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O. Draw a use-case diagram and a set of activity diagrams for a health club
membership system. When members join the health club, they pay a fee for a
certain length of time. Most memberships are for one year, but memberships as
short as two months are available. Throughout the year, the health club offers a
variety of discounts on their regular membership prices (e.g., two memberships for

the price for

amounts of one
the for Valentine’s
same length of Day). It is common
membership. for wants
The club members to pay
to mail outdifferent
reminder
letters to members asking them to renew their memberships one month before their
memberships expire. Some members have become angry when asked to renew at a
much higher rate then their original membership contract, so the club wants to
track the price paid so that the manager can override the regular prices with special
prices when members are asked to renew. The system must track these new prices
so that renewals can be processed accurately. One of the problems in the health club
industry is the high turnover rate of members. While some members remain active
for many years, about half of the members do not renew their memberships. This is
a major problem, because the health club spends a lot in advertising to attract each

new member.
into the The system
club. The manager wants
will then the system
identify thetoheavy
trackusers,
each time a membera comes
and generate report so
the manager can ask them to renew their memberships early, perhaps offering them
a reduced rate for early renewal. Likewise, the system should identify members who
have not visited the club in more than a month, so the manager can call them and
attempt to re-interest them in the club.

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P. Create a set of detail use-case descriptions for the system in Exercise O.

Major use cases are listed by actor:

Members

  Join club
o  Pay fee that varies by membership length (should have look-up table or

equivalent logic for durations and price for each)

  Calculate discount (should have look-up table or equivalent logic for discount
source and amount)

Club staff

  Send reminder letters (one month before expiration)

o  Calculate new rate

  Adjust for Manager overrides (where needed)

o
o Substitute override for renewal rate in letter (where needed)
o  Send reminder letter  

Manager

  Override regular prices with special prices

o  Observe current and renewal rates

o  Set override rate (where judged to be warranted)

o  Add override rate into database


  Askoheavy users for early renewal
  Determine heavy users from report
o  Adjust renewal price for heavy users

o  Ask heavy users for renewal

o  Determine non-users from report (zero uses in at least a month)

o  Call non-users and attempt to persuade to increase use

Club staff/member (not clear in case who enters this data) –  maybe one or both; may
happen through automated source data entry, e.g. use of a smart card.

  Add record to member-usage database (each time member uses club)

Club staff/manager (not clear in case who handles this task) –  could be one or the other or
 both.

  Prepare heavy user report

o  Sort members by amount of usage

o  Print heavy user report

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The second level activities provide the beginnings of detailed use cases where activities
in the case can be grouped into a higher level use case. For the other higher level
activities, students should provide more details based on their understanding of this sort
of business. Providing more detailed steps will vary with the student’s understanding of

 businessThis
operations andincludes
mini-case the amount
someofactivities
detail they
thatexpress.
are not clearly attributed to any
 particular actor. The students will probably sort this out in one or another manner. The
instructor should decide if only one of the directions to go is correct (and be prepared to
explain this to the students) or check to see which answers students come up with and ask
them for explanations. Clearly this is a case where in practice the analyst will return to
the users to ask for their preferences.

Q. Perform a verification and validation walkthrough of the functional models of

the health club membership system described in exercises O and P.

In order to verify and validate the functional model, a set of rules have been defined to
ensure the consistency among the activity diagram (described in O), the use-case
description (described in P), and the use-case diagram (defined in O).

First, when comparing an activity diagram to a use-case description, there should be at

least one event recorded in the normal flow of events, subflows, or alternate/exceptional
flows of the use-case description for each activity or action that is included on an activity
diagram, and each event should be associated with an activity or action.

Second, all objects portrayed as an object node in an activity diagram must be mentioned
in an event in the normal flow of events, subflows, or alternate/exceptional flows of the
use-case description.

Third, sequential order of the events in a use-case description should occur in the same
sequential order of the activities contained in an activity diagram.

Fourth, when comparing a use-case description to a use-case diagram, there must be one
and only one use-case description for each use case, and vice versa.

Fifth, all actors listed in a use case description must be portrayed on the use-case
diagram. Furthermore, each one must have an association link that connects it to the use
case and must be listed with the association relationships in the use-case description. In
some organizations, we should also include the stakeholders listed in the use-case
description as actors in the use-case diagram.

Sixth, all other relationships listed in a use-case description (include, extend, and
generalization) must be portrayed on a use-case diagram.

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Finally, there are many diagram-specific requirements that must be enforced. For
example, in an activity diagram a decision node can be connected to activity or action
nodes only with a control flow, and for every decision node there should be a matching
merge node. Every type of node and flow has different restrictions.

R. Draw a use-case diagram and set of activity diagrams for the following system.
Picnics R Us (PRU) is a small catering firm with five employees. During a typical
summer weekend, PRU caters fifteen picnics with twenty to fifty people each. The
business has grown rapidly over the past year and the owner wants to install a new
computer system for managing the ordering and buying process. PUR has a set of
ten standard menus. When potential customers call, the receptionist describes the
menus to them. If the customer decides to book a picnic, the receptionist records the
customer information (e.g., name, address, phone number, etc.) and the information
about the picnic (e.g., place, date, time, which one of the standard menus, total

price) on return
sign and a contract. Thewith
it along customer is then
a deposit faxed
(often a copy
a credit of the
card contract
or by check)and must
before the
picnic is officially booked. The remaining money is collected when the picnic is
delivered. Sometimes, the customer wants something special (e.g., birthday cake). In
this case, the receptionist takes the information and gives it to the owner who
determines the cost; the receptionist then calls the customer back with the price
information. Sometimes the customer accepts the price, other times, the customer
requests some changes that have to go back to the owner for a new cost estimate.
Each week, the owner looks through the picnics scheduled for that weekend and
orders the supplies (e.g., plates) and food (e.g., bread, chicken) needed to make
them. The owner would like to use the system for marketing as well. It should be
able to track how customers learned about PUR,and identify repeat customers, so
that PUR can mail special offers to them. The owner also wants to track the picnics
on which PUR sent a contract, but the customer never signed the contract and
actually booked a picnic.

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S. Create a set of use-case descriptions for the system in Exercise R.

Major use cases are listed by actor:

PRU

  Take orders
  Buy supplies
  Cater picnic (size: 20-50)
  Collect payment (minus deposit)
  Perform marketing tasks

Receiving Order Use Cases

  Customer
o  Calls in order

   Receives menu description (see Receptionist activity) 

o

o Decides whether to books picnic

o  Provides customer information ( see Receptionist activity)
o  Provides picnic information ( see Receptionist activity)
o  Provides special product information ( see Receptionist activity) 
o  Receives fax of contract
o  Signs contract
o  Faxes contract to PRU
o  Pays picnic deposit
  Faxes credit card info
  Sends check

  Receptionist
o  Describes menus (10 standard ones)

o  Assists customer decision making (or waits)

o  Records customer information (on contract)

o  Records picnic information (on contract)

o  Process special product (may go through iterations)

  Gives special product information to owner (see owner activity)



o  Receives special product cost information from owner

o  Calls the customer back

o  Provides special product cost information to client

  Client provides feedback regarding special product cost

o
information
o  Faxes contract to customer

  Owner
o  Receives special product information

o  Determines cost of special product

o  Sends special product cost information to receptionist

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Buying Supplies Use Cases

  Owner
 
o
Reads weekly orders
o  Purchases materials

  Purchases supplies


  Purchases food


Marketing Use Cases

  Owner
o  Track customers learning about PRU

o  Identify repeat customers

o  Mail repeat customers special offers

o 
Identify customers who received but did not sign and return contracts

T. Perform a verification and validation walkthrough of the functional models of the

catering system described in exercises R and S.

In order to verify and validate the functional model, a set of rules have been defined to
ensure the consistency among the activity diagram (described in R), the use-case
description (described in S), and the use-case diagram (defined in R).

First, when
least one comparing
event recordedaninactivity diagram
the normal flowtoofaevents,
use-case description,
subflows, there should be at
or alternate/exceptional
flows of the use-case description for each activity or action that is included on an activity
diagram, and each event should be associated with an activity or action.

Second, all objects portrayed as an object node in an activity diagram must be mentioned
in an event in the normal flow of events, subflows, or alternate/exceptional flows of the
use-case description.

Third, sequential order of the events in a use-case description should occur in the same
sequential order of the activities contained in an activity diagram.

Fourth, when comparing a use-case description to a use-case diagram, there must be one
and only one use-case description for each use case, and vice versa.

Fifth, all actors listed in a use case description must be portrayed on the use-case
diagram. Furthermore, each one must have an association link that connects it to the use
case and must be listed with the association relationships in the use-case description. In

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some organizations, we should also include the stakeholders listed in the use-case
description as actors in the use-case diagram.

Sixth, all other relationships listed in a use-case description (include, extend, and
generalization) must be portrayed on a use-case diagram.

U. Draw a use-case diagram and a set of activity diagrams for the following system.
Of-the-Month Club (OTMC) is an innovative young firm that sells memberships to
people who have an interest in certain products. People pay membership fees for
one year and each month receive a product by mail. For example, OTMC has a
coffee-of-the-month club that sends members one pound of special coffee each
month. OTMC currently has six memberships (coffee, wine, beer, cigars, flowers,
and computer games) each of which costs a different amount. Customers usually
belong to just one, but some belong to two or more. When people join OTMC, the
telephone operator records the name, mailing address, phone number, e-mail

address, credit card

Some customers information,
request a double start date,membership
or triple and membership service(s)
(e.g., two pounds(e.g., coffee).
of coffee,
three cases of beer). The computer game membership operates a bit differently from
the others. In this case, the member must also select the type of game (action,
arcade, fantasy/ science-fiction, educational, etc.) and age level. OTMC is planning
to greatly expand the number of memberships it offers (e.g., video games, movies,
toys, cheese, fruit, and vegetables) so the system needs to accommodate this future
expansion. OTMC is also planning to offer 3-month and 6-month memberships.

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V. Create a set of detail use-case descriptions for the system in Exercise R.

Major use cases are listed by actor:

 Note that many details of the case are values (such as the specific clubs) which should be
captured in database or tables as these may change over time. An interesting question to
 pose to students will be what to do with the parts of the system pertaining to computer
games if these change from selling them as products on CD to providing access for a
 period of time to a web-site.

OTMC

  Sell memberships
  Provide products to members (likely outside scope of the present system)

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Customer

  Joins club
o  Provides customer information

o  Provides membership services information (e.g. which clubs joined)

  

  (For
(For each
each service)
service) Provides
Provides multiple membership
membership information
length desired
  (For computer game membership) Selects game type(s)


  Pay membership
o  Check customer memberships

o   Note cost of each membership

o  Calculate total costs

o  Send invoice to customer

  Receive products (monthly)

  Telephone Operator

  Facilitates customer joining club

o
  Receives customer information


  Receives membership services information



  (For each service) Receives multiple membership



information
  (For each service) Receives membership length desired
information
  (For each computer game membership) Receives game
type information

 Note: Items in red are part of the “to- be” system or may be stubs programmed f or future
expansion. It is a business decision whether to prepare for the business policy changes in
the new system or to wait for later updates. This presents an interesting discussion to
have with students regarding how they want to handle future anticipated features which
may or may not be realized by the organization. My own inclination in this case would
 be to include them in the design, but this is most likely something that business sponsors
may have to decide.

W. Perform a verification and validation walkthrough of the functional models of

the Of-the-Month Club system described in exercises U and V.

In order to verify and validate the functional model, a set of rules have been defined to
ensure the consistency among the activity diagram (described in U), the use-case
description (described in V), and the use-case diagram (defined in U).

First, when comparing an activity diagram to a use-case description, there should be at

least one event recorded in the normal flow of events, subflows, or alternate/exceptional
flows of the use-case description for each activity or action that is included on an activity
diagram, and each event should be associated with an activity or action.

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Second, all objects portrayed as an object node in an activity diagram must be mentioned
in an event in the normal flow of events, subflows, or alternate/exceptional flows of the
use-case description.

Third, sequential
sequential order
order of of the events
the activities in a use-case
contained description
in an activity should occur in the same
diagram.

Fourth, when comparing a use-case description to a use-case diagram, there must be one
and only one use-case description for each use case, and vice versa.

Fifth, all actors listed in a use case description must be portrayed on the use-case
diagram. Furthermore, each one must have an association link that connects it to the use
case and must be listed with the association relationships in the use-case description. In
some organizations, we should also include the stakeholders listed in the use-case
description as actors in the use-case diagram.

Sixth, all other relationships listed in a use-case description (include, extend, and
generalization) must be portrayed on a use-case diagram.

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