1419 West Main Street Richmond, Virginia 23230 804.355.0511 ©2010 CapTech Ventures The Business End of Data Modeling Bob Lambert.

1419 West Main StreetRichmond, Virginia 23230804.355.0511

©2010 CapTech Ventures

www.captechventures.com

The Business End of Data ModelingBob Lambert

©2010 CapTech Ventures, Inc. All rights reserved.

The Business End of Data Modeling, Bob Lambert, SQLSaturday#30, Richmond, VA, 1/30/2010

What about Bob?

Manager/Architect at CapTech focusing on system architecture, data modeling, and database design. Background: mainframe and Oracle PL/SQL development, systems analysis, project/program

management, training, SQL Server data warehousing.

Live in Powhatan where I help my wife run a boarding barn

Play in a small jazz outfit called Super64

Page 2



The Business End of Data Modeling

The requirements side of data modeling • and how it prepares you the database

developer to design and build the right solution.

When critical business definition elements are missing • what you the database professional can

do to produce a successful result.

Page 3© 2008 CapTech Ventures, All rights reserved.



Look like a project you’ve been on?




Standish Group Study of Project Outcomes

Page 5

http://www.projectsmart.co.uk/the-curious-case-of-the-chaos-report-2009.html

1994 1996 1998 2000 2002 2004 2006 2009 Successful 16% 27% 26% 28% 34% 29% 35% 32%

Challenged 53% 33% 46% 49% 51% 53% 46% 44%

Failed 31% 40% 28% 23% 15% 18% 19% 24%

Success: The project is completed on-time and on-budget, with all features and functions as initially specified.

Challenged: The project is completed and operational but over-budget, over the time estimate, and offers fewer features and functions than originally specified.

Failed: The project is canceled at some point during the development cycle.

http://findarticles.com/p/articles/mi_hb286/is_6_34/ai_n29049353/?tag=content;col1



Standish’s conclusion

“The three major reasons that a project will succeed are user involvement, executive management support, and a

clear statement of requirements.”

http://findarticles.com/p/articles/mi_hb286/is_6_34/ai_n29049353/?tag=content;col1

Page 6



What are requirements?

1. A shared vision of desired project outcome• Documented cost/benefit impact• Endorsed by a business sponsor and supported by key participants

2. Consensus scope, objectives, and constraints, including • Definition of system boundaries and interfaces• Identification of key constraints

3. Definition of the business processes and information required to achieve objectives

4. Identification of the IT application’s role in business processes and information management

• Process automation• Data management

Page 7



Projects often shortchange the Information part of requirements

Although there are exceptions, in my experience, • Business Requirements Document Templates often lack Data Model sections• Projects applying object-oriented approaches often focus on behavior via Use Case

analysis. Class models tend not to factor business concepts into normalized units.• Business reengineering is a process-based technique that often omits data-

focused analysis.• Application Projects often feature the “data person” who does all the “data stuff”,

while responsibility for functional requirements are shared among the entire team• Agile teams sometimes focus on minimal requirements analysis in favor of delivery

of perceived value on time

Page 8



Data Requirements: The Logical Data Model

A graphical representation of • People, places, and things of interest to the organization

(entities)• Core business rules governing business entities, the

relationships between them• Characteristics (attributes) of business entities and relationships• Independent of any physical implementationA logical data model can be at different levels of detail• Conceptual – a general view of business concepts • High level –further detail, still accessible to a broad audience• Low level – detailed and precise

(Names of data model levels vary from source to source)

Page 9

Project

PK ProjectId

ProjectName BudgetAmount PlannedStartDate PlannedEndDateFK1 PersonIdFK1 ClientShortName

Client

PK ClientShortName

CiientName

Person

PK PersonId

FirstName MiddleName LastName PersonType

Consultant

PK EmployeeId

FK1 PersonId

PersonType

Contact

PK,FK1 PersonIdPK,FK2 ClientShortName

sponsors / sponsored by

Employs / Employed by

Assignment

PK,FK1 ProjectIdPK,FK2 EmployeeId

StartDate EndDate

has / is for

assigned to / is for

Project

PK ProjectId


Client

PK ClientShortName

CiientName

Person

PK PersonId


Consultant

PK EmployeeId

FK1 PersonId

PersonType

Contact




Assignment


StartDate EndDate

has / is for


Any resemblance of this data model example to CapTech’s internal practices is purely accidental



Logical Data Modeling Promotes IT/Business Alignment

Page 10

Logical Data Model

Precise Business Language

Definition of rational and efficient

business rules and processes

Database Design

Business-consistent

database design or class modeling

Business ProcessDefinition

ApplicationDevelopment



Logical Data Model Characteristics and Components

Characteristics:- A Logical data model is implementation-independent and primitive

Components:- Entity Relationship Diagram (ERD)

• Entity: a single object or event of significance to the business• Relationship: a significant association between two entities• Attribute: any detail that qualifies, identifies, classifies, or expresses the state of an

entity or relationship - Metadata: Definitions and other supporting information describing objects represented

on an entity relationship diagram.

Page 11



Implementation Independence

Which of these two statements belongs in a requirements document? Why?• “Each accident report includes a photo of the damage

taken by the estimator”• “Each accident report record will include a field

containing the name of the damage photo file. That file must be in JPEG format.”

Implementation Independence means: • “What not How”• not related to technical specifics• AKA “logical” or “essential”

Page 12© 2008 CapTech Ventures, All rights

reserved.



Entities: Business Critical Objects and Events

Definition- An object or event critical to the business

- A thing of significance, either real or conceptual, about which the business or system being modeled

needs to hold information.

- Entities are the boxes on a logical data model

Categories of entities- Fundamental: exist on their own without reference to other entities (e.g. employee, building)

- Attributive: require the existence of another entity (employee dependent, cubicle)

- Associative: define the relationship between two other entities (an employee’s cubicle assignment)

- Subtype: a specific entity that is a special case of a more general entity type (“car” might be a

subtype of “vehicle”




Relationships = Business Rules

Definition• An association among two or more entities

• Define how critical business objects and events interact

• Relationships are the lines between boxes on a logical data model

Relationship Notes• There are three common types: one to one, one to many, and many to many

• There may be more than one relationship between any two entities

Examples• What happens when a mechanical issue is registered for an aircraft?

• How many students can enroll in a given class?

• How does a customer place an order?




Attributes: Describe Entities

Definition• An identifiable property of an entity

• Consists of a name, data type, domain, and optionally presentation format and default value

Domain• The set of possible values of an entity

• Identifies any business rules or restrictions that define correct values for the attribute

Good Practices with Attributes• Attribute names use a standard convention and standard abbreviations

• Each entity is uniquely identified by an attribute or a group of attributes

• Document and maintain attribute metadata




Primitiveness: Derived vs. Atomic Attributes

Atomic (or Primitive) Attributes• Individual object or event: Cost of an item, Quantity purchased• The deepest level of detail needed by the business

Derived and Summary Data• Combines characteristics of many objects and events

• Can integrate data across different reporting dimensions• Defined as a formula based on other data

Use only atomic attributes in logical data modeling




Metadata: Business Context for Model Content

Metadata makes the Logical Data Model accessible to a broad audience- Why was the model created and what was its scope

- Modeling conventions and quality standards- Abbreviations- Entity and attribute definitions- Model limitations and next steps



Logical Data Model = Clear Business Language

You can derive a data model from a precise text description of a business area

and

You can derive a precise text description of a business area from a logical data model


Project

PK ProjectId


Client

PK ClientShortName

CiientName

Person

PK PersonId


Consultant

PK EmployeeId

FK1 PersonId

PersonType

Contact




Assignment


StartDate EndDate

has / is for


Project

PK ProjectId


Client

PK ClientShortName

CiientName

Person

PK PersonId


Consultant

PK EmployeeId

FK1 PersonId

PersonType

Contact




Assignment


StartDate EndDate

has / is for




The data model in English

A person may be a contact

A client employs many contacts

A project may be sponsored by a client contact

An assignment is for a project

A consultant is assigned to a project

A project may be internal

(not associated with a client or contact)

A consultant is a person

Page 19

Project

PK ProjectId


Client

PK ClientShortName

CiientName

Person

PK PersonId


Consultant

PK EmployeeId

FK1 PersonId

PersonType

Contact




Assignment


StartDate EndDate

has / is for


Project

PK ProjectId


Client

PK ClientShortName

CiientName

Person

PK PersonId


Consultant

PK EmployeeId

FK1 PersonId

PersonType

Contact




Assignment


StartDate EndDate

has / is for




In a good, detailed, logical data model:

•Every entity is identified by a natural key•Every distinct business object or event is shown as an entity•Every attribute describes the entity that it belongs to

Detailed definition of objects, events,

attributes, and business rules gets you a solid first cut

database design

(Informally) a database is normalized when

•No table has repeating groups•Every column in a table is functionally dependent on the whole key• No column depends on anything but the key

A Detailed Logical Data Model is Normalized

Page 20



The Business End of Data Modeling

The requirements side of data modeling • and how it prepares you the database

developer to design and build the right solution.

When critical business definition elements are missing • what you the database professional can

do to produce a successful result.




Your mission

Build a database that is a foundation for meeting business needs, documented or not:- Deliver to the shared vision of desired project outcome- Meet project objectives - Manage data required to support in-scope processes

Design, deploy, and maintain a database that- Stores and maintains:

- Data about business objects and events- Attributes describing those objects and events- Relationships among those objects and events

- Operates efficiently with the application being developed

Page 22



Six tools for succeeding in database design without solid requirements

Tool NotesBuild rapport with business Friendly (but still professional) contacts make it easier to

address tough questions when needed.

Build step by step in small chunks that deliver business value

Rework, if needed, is easier and you can align plans with the business step by step.

Track risks and issues Tactfully, make sure everyone is aware of the business questions that aren’t yet resolved.

Take time to normalize before designing The normalized model translates to business objects, events, attributes, and rules, making your app more likely to meet business needs.

You don’t have time to skip documentation Change happens: how can you change something when you don’t remember why you did it?

Hold design reviews with business and technical players

Make sure everyone understands and endorses database design decisions.

Page 23



Three Typical Scenarios

The Great Leap

• “We’re very excited about automating our business processes but we

don’t quite know what to expect. How will Irma keep the ledger up to

date when the new system automatically assigns customer numbers?”

Reckless Abandon

• “Budget and schedule are very tight. I need you to start coding as soon

as possible and not waste time on front-end documentation”

Benign Neglect

• “Your business contacts are on 80% travel and will be very tough to

reach. Here’s our two page vision statement. That should give you

everything you need to build the new system.”Page 24© 2008 CapTech Ventures, All rights reserved.



The Great Leap:Modernizing Outdated Business Processes

Page 25

Tool Notes

Build rapport with business participants Friendly (but still professional) contacts make it easier to address tough questions when needed.


Replace the outmoded ledger last. Build trust and understanding by starting with the easy chunks that make their life easier.

Track risks and issues Make sure everyone is aware of the business questions that aren’t yet resolved.

Take time to normalize before designing Start database design by building your own “just good enough” logical data model. Translate it to English before reviewing it with business players.

You don’t have time to skip documentation Change happens: how can you change something when you don’t remember why you did it?


Plan these carefully to limit the amount of new “jargon” you expose to business participants.

“We’re very excited about automating our business processes but we don’t quite know what to expect. How will Irma keep the ledger up to date when the new system automatically assigns customer numbers?”



Reckless Abandon:When requirements are devalued

Page 26

“Budget and schedule are very tight. I need you to start coding as soon as possible and not waste time on front end documentation”

Tool Notes

Build rapport with business participants Friendly (but still professional) contacts makes it easier to address tough questions when needed.



Track risks and issues Use the risk and issue process as a way to flesh out requirements, promote risk/issue management as a way to make sure the tight project stays on track.


You don’t have time to skip documentation Be careful to avoid any impression that you are “wasting time” in documentation. Make it as informal and brief as possible, just good enough for your successor to understand.


Use design reviews as a forum for raising and resolving requirements questions.



Benign Neglect:When business participants are not available

Page 27

Tool Notes

Build rapport with business participants Use collaborative tools like discussion boards, shared document storage, and desktop sharing to enable remote participation. Adjust schedules as needed to accommodate people in different time zones.



Track risks and issues Tactfully, make sure everyone is aware of the business questions that aren’t yet resolved.


You don’t have time to skip documentation Document everything, include summaries for easy review and make them accessible for remote participants.


Schedule face to face reviews well in advance and plan them carefully to make meetings valuable to all involved.

“Your business contacts are on 80% travel and will be very tough to reach. Here’s our two page vision statement. That should give you everything you need to build the new system.”



The Business End

“The three major reasons that a project will succeed

are user involvement, executive management

support, and a clear statement of requirements.”

One key element of requirements describes the

people, places, and things of interest to the

organization, business rules governing them, the

relationships among them, and their attributes. This

statement of requirements is the logical data model.

A detailed logical data model is a normalized

database pre-design.

Page 28

You can improve your chances of overcoming

missing or insufficient requirements by:

Building rapport with business participants

Building in small chunks that deliver business value

Tracking risks and issues

Taking time to normalize before designing

Not skipping documentation

Holding design reviews with business and technical

players



In conclusion

•For more on the business side of data modeling I

recommend Data Modeling for the Business by Steve

Hoberman et al. See www.stevehoberman.com.

•A surprisingly good reference on risk and issue

management:

- http://office.microsoft.com/en-us/project/

HA100072491033.aspx

•This presentation is posted at http://robertlambert.net .

Questions welcome at [email protected] and

[email protected].

•Please rate this talk at

www.speakerrate.com/boblambert12Page 29

1419 West Main StreetRichmond, Virginia 23230804.355.0511

©2010 CapTech Ventures

www.captechventures.com

Thanks for attending!Bob Lambert

[email protected]

1419 West Main Street Richmond, Virginia 23230 804.355.0511 ©2010 CapTech Ventures The Business End of Data Modeling Bob Lambert.

Documents

data requirements

logical data modeling

business processes

data stuff

data person

business sponsor

business reengineering

captech ventures