Radoš Šumrada
Faculty of Civil and Geodetic Engineering
Jamova 2, Si 1000 Ljubljana, Slovenia
COST G9 - Work group 2
Cadastral science meeting
Aalborg, Dk
25. 08. - 26. 08. 2005
Modeling methodology for
real estate transactions
Modeling methodology for real estate transactions
Contents
Introduction
Methodology development (main phases and steps)
Proficiency acquisition (expertise and existing models)
Problem domain analysis (classes and relations)
Use case analysis (actors and use cases)
Analysis of work flows (activities and roles)
Analysis of interactions (data flows and time span)
Diagrams (UML) of a sample real estate transaction case
(sale of a whole parcel - Si setting)
Conclusions
COST G9 - Work group 2, Cadastral science meeting, Aalborg, Dk, 25. 08. - 26. 08. 2005
2
Introduction
The development of a suitable methodology for conceptual
modeling in the real estates domain is a demanding process.
The adopted methodology starts with the classification of objects.
The provenance are detailed use case descriptions (expertness)
for the sample real estate transactions.
The proposed modeling approach uses UML formalism (Unified
Modeling Language).
The outcomes are presented on UML package, collaboration,
class, use case, activity and interaction diagrams.
COST G9 - Work group 2, Cadastral science meeting, Aalborg, Dk, 25. 08. - 26. 08. 2005
3
Main steps of problem domain analysis (1)
Domain analysis classifies objects, defines their properties and relations
and concludes as a formal application schema.
The static structure defines important classes, their
properties and relationships between classes.
Sale of a whole parcel
as a collaboration
diagram - Si setting
:Seller
:Third party
The dynamic behavior specifies the stable states of
classes, their functionality and the interactions among
them (collaborations) in order to accomplish services.
Sale of a
whole parcel
The applied modeling process should be carried out
incrementally and iteratively.
:Buyer
The first phase should be the proficiency acquisition;
Gather data and expertise on real estate transaction modeling, existing
transaction processing systems and detailed users’ requirements.
COST G9 - Work group 2, Cadastral science meeting, Aalborg, Dk, 25. 08. - 26. 08. 2005
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Problem domain analysis
Use case analysis
Analysis of work flows
Analysis of interactions
Main steps of problem domain analysis (2)
The problem domain analysis phase has many steps:
Identify problem domain objects and draw high-level
class diagrams that introduce primary data structure.
Perform classification (classes), generalization and aggregation
in order to derive the first cut structure of domain classes.
Specify their main properties (attributes) and relationships
(associations and other dependencies) among classes.
Describe their basic functionality (activities) and
important messages (communication) among classes.
Identify packages (subsystems) and the general
structure of the system as a whole.
COST G9 - Work group 2, Cadastral science meeting, Aalborg, Dk, 25. 08. - 26. 08. 2005
5
Motgagee
Pre-emption
holder
Tax
authority
Cadastral
authority
Sale
contract
«subsystem»
Land register
(DBMS)
Land
registry
Buyer
Expert
Seller
UML package and general class
diagrams outline the sale of a whole
parcel example (Si setting).
UML package diagram
for sale of a whole
parcel - Si setting
Third Party
<<RRR>>
Encumbrance
Mortgagee
Partial class diagram for
ownership of a whole
parcel - Si setting
ThirdParty
LegalFact
1..*
1..*
Easement
Mortgage
Deed
+form : kind
«enumeration»
right
+appurtenant
+personnal
+commercial
+form : kind
+type : right
+side : list
LandCharge
Deed
1
*
1
Obligation
Contract
+form : kind
1
*
*
*
*
1..*
Cadastral
Municipality
1..*
*
1
1
*
Administrative
Unit
Parcel
PartOfParcel
1..*
1
1..*
1
*
1..*
1
TenantOrUser
Ownership
Owner
«enumeration»
kind
+contract
+by law
1
0..*
«enumeration»
list
+dominant
+servient
1 1..*
COST G9 - Work group 2, Cadastral science meeting, Aalborg, Dk, 25. 08. - 26. 08. 2005
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Problem domain analysis
Use case analysis
Analysis of work flows
Analysis of interactions
Use case analysis (1) - Actors and use cases
A use case is a sequence of actions that an actor
performs in order to achieve a particular service.
Actors are users or other systems that interact with the modeled system.
Use case analysis defines one or more paths through the activities
that accomplish an use case and as well all the possible scenarios.
The main steps in use case analysis phase are the following:
Identify and describe use cases, actors and the important
interactions among the actors and use cases.
Develop use cases from the general to the detailed descriptions.
COST G9 - Work group 2, Cadastral science meeting, Aalborg, Dk, 25. 08. - 26. 08. 2005
7
COST G9 - Work group 2, Cadastral science meeting, Aalborg, Dk, 25. 08. - 26. 08. 2005
8
Use case analysis (2)
Define priorities of use cases.
Elaborate each use case in all the required detail
(main course and all the alternative scenarios).
Present use cases on a set of use case diagrams.
Organize use cases into the suitable groups.
Present the organization of use cases and their
hierarchy on package diagrams.
COST G9 - Work group 2, Cadastral science meeting, Aalborg, Dk, 25. 08. - 26. 08. 2005
9
UML use case diagram
for sale of a whole
parcel - Si setting
pay real estate
transfer tax
request sale
permission
«subsystem»
Real estate
value register
deny sale
permission
Administrative
authority
contract
mortgage
Mortgagee
register
purchase
Tax
authority
Seller
check public
regulations
issue sale
permission
check
pre-emptions
inform
claimants
prepare sale
contract
sign
pre-contract
sign sale
contract
switch of
buyers
Buyer
Expert
verify sale
contract
examine parcel
and check data
Notary
update
database
submit ownership
registration
Cadastral
authority
perform sale
transaction
Pre-emption
holder
change
ownership
«subsystem»
Cadastral
database
send data
and decree
Land
registry
update
database
COST G9 - Work group 2, Cadastral science meeting, Aalborg, Dk, 25. 08. - 26. 08. 2005
«subsystem»
Land register
(DBMS)
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Problem domain analysis
Use case analysis
Analysis of work flows
Analysis of interactions
Analysis of work flows - Activities and roles
Objects work together (collaborate and interact) in order
to produce the functionality that actors require as system services.
Each object normally provides only a portion of functionality needed to
accomplish certain service.
Collaboration is a set of objects, actors or participants that work together to
achieve some services with meaningful outcome in the context of the system.
A role is the named functionality that a class provides in a collaboration.
Activity diagrams are used to describe work flows such as collaborations in
use cases or business flows.
COST G9 - Work group 2, Cadastral science meeting, Aalborg, Dk, 25. 08. - 26. 08. 2005
11
General UML activity
diagram for a sale of
whole parce - Si setting
Owner decides to sell a parcel
Real estate and
data examination
Buyer ought to be informed.
pre-contracting
Preparing and signing
the sale contract
Notary examines the sale
contract and all parties sign it.
Covering the stamp duty
Buyer pays real estate transfer
tax (2 %) to the tax authority.
Contract verification
Notary checkes and
verifies the sale contract.
Purchase sum transfer
financial transaction
(with notary assistance)
contracting
Application for
ownership registration
Registration of ownership
Buyer must register ownership.
Notification of
changed ownership
Land cadastre
and (new) owner
registration
COST G9 - Work group 2, Cadastral science meeting, Aalborg, Dk, 25. 08. - 26. 08. 2005
12
Problem domain analysis
Use case analysis
Analysis of work flows
Analysis of interactions
Analysis of interactions - Data flows and time span
Interaction is a sequence of messages sent between objects in the context of a
collaboration in order to accomplish the required functionality or service.
Processing steps for the realization of each use case should describe the required
collaboration among the participating classes.
Messages (and data) that need to pass between objects must be defined.
UML sequence diagrams show messages and data exchange among objects.
If needed, UML state diagrams can depict dynamics of (important) objects.
COST G9 - Work group 2, Cadastral science meeting, Aalborg, Dk, 25. 08. - 26. 08. 2005
13
:Seller
:Buyer
:SaleContract
:Notary
:Tax authority
:Land registry
prepare sale contract
prepare sale contract
sign sale contract
prepare sale contract
assist both
parties
sign sale contract
submit real estate
sales tax application
transfer purchase amount
examine sale
contract
determine
sale tax
issue real estate
sales tax bill
The seller and
the buyer
receive copies
of the signed
and verified
sale contracts.
pay real estate sales tax bill
start contract verification
receive copy of
verified sale contract
verity sale contract
check sale
contract
receive copy of verified sale contract
transfer purchase sum
contracting
submit for ownership registration
send data and title decree
registration
UML sequence diagram for sale
of a whole parcel - Si setting
COST G9 - Work group 2, Cadastral science meeting, Aalborg, Dk, 25. 08. - 26. 08. 2005
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Conclusions
At the end we should stress again that for modeling real estate transactions it
is crucial to follow the chosen methodology as the guiding process.
Only the main modeling phases and developing steps have been presented.
The benefits of the standardized modeling language (UML) and its graphical
notation are obvious, although the elaboration of detailed UML diagrams can
be a challenging task.
The availability of powerful modeling tool (OOAD software) is also important.
COST G9 - Work group 2, Cadastral science meeting, Aalborg, Dk, 25. 08. - 26. 08. 2005
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Saturday, July 29, 2017 - 04:08:11
Questions and opinions?