INFORMATION GOVERNANCE

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Chapter6-BINF4515-kmk.pptx

Chapter 6

Data Architecture Management

St. Rita’s EIM Team Questions

What falls within the scope of architecture management?

What is the data life cycle and how does it fit within data architecture management?

What are system development methods?

How is data governance (DG) applied to data architecture management?

Life Cycles for Managing Systems development

Managing Systems Development

Project management life cycle

Systems development life cycle (SDLC)

Systems Development life cycle (SDLC)

Systems Development Life Cycle

Systems Development Life Cycle

System initiation

The business case and project solution  are validated to ensure they meet business needs

Resources including staff, budget, and time are identified

Project schedule is developed

Final approval by authorizing authority

Systems Development Life Cycle

Requirements analysis

Business requirements that the system will support are identified

Accomplished by business analysts and end users identifying current business processes (the “as-is” system), determining what improvements or changes need to be made to the current processes, and identifying the characteristics and functions of the new (“to-be”) system

Development of artifacts such as data flow diagrams, data models, and use cases

This slide can accompany the Student Workbook section for chapter 6.

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Systems Development Life Cycle

System design

Functionalities and processes are translated   by the project team into a technical design or architecture and includes:

Identifying the hardware and system software

Creating the physical database, security strategy, and performance requirements

Prototyping system components  

This slide can accompany the Student Workbook section for chapter 6.

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Systems Development Life Cycle

System construction

The activities required to build and test the system including:

Building and testing the individual system components

Integrating and testing the components as a whole

Producing user and technical documentation

This slide can accompany the Student Workbook section for chapter 6.

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Systems Development Life Cycle

System acceptance

The system is validated  (tested) by the  project team and end users to determine if it meets all of the functional and technical specifications; this may include:

System walk-throughs

Manual and automated testing

Revision of technical and user documentation

This slide can accompany the Student Workbook section for chapter 6.

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Systems Development Life Cycle

System implementation

System deployment into the real world environment and includes:

User education

Putting the system into production

Transitioning ongoing support and maintenance of the system to the appropriate units of the organization  

This slide can accompany the Student Workbook section for chapter 6.

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System initiation

Example System Initiation Process

SDLC Development methods

SDLC Development Methods Waterfall Method

Oldest development method

Implemented sequentially

Benefits

All planning done before software development

Minimizes scope creep

Disadvantages

Time delay to deployment

Costs of redesign

Minimal end user input

SDLC Development Methods Parallel Method

Project divide into sub-projects that are developed and implemented parallel with each other

Benefit

Reduces development time

Disadvantage

May introduce integration problems if development of each subpart is developed completely independent

SDLC Development Methods Validation and Verification Model

Also called V-model

Integrates testing design with all the life cycle stages

Benefits

Overall quality of system improves

Disadvantage

Retains rigidity of waterfall method

Rapid Application Development Methods (RAD)

A group of developmental methodologies that address the long development time problem

Goes through the analysis, design, construction, and acceptance stages of the SDLC quickly and gets essential parts of the system to the end user as soon as possible

Uses a combination of tools and techniques to move through the SDLC stages quickly

RAD Methods

Iterative method

Prototyping

Spiral method

Agile development

Requirements analysis

Requirements Analysis

The set of processes used for identifying what function(s) an information system must perform and how it is to provide them

Fundamental building block of all information systems

The most difficult step in information systems development, and most defects originate in the requirements analysis and design phases

Requirements Analysis Gathering Techniques

Document analysis

Observation

Interviewing

Joint application development (JAD)

Requirements Analysis Outputs

Group of key artifacts that guide the system’s design and construction that include:

Data flow diagrams

Process flow diagrams

Use cases

Data models

Functional specification documents

data ARCHITECTURE DOCUMENTATION

Data Architecture Documentation

Tools, techniques, and documentation strategies are used to provide discipline, structure, communication, and integration among analysis tasks

Documents produced are called artifacts

Artifacts are crucial for communication between the development team and stakeholders and providing documentation for future changes

Data Architecture Documentation Use Cases

Technique used  by analysts for capturing and documenting user requirements

Identify and clarify the interactions between an end user and the proposed system

A story of the steps or actions that are taken between a user and a system to achieve an end result   

Data Architecture Documentation Use Cases

Use case types

Essential use case (business use case)

Describes the business process and interaction of the end user with the system without specifying any technology details

System use case

Provides the technology and operational details of the system and is used by the technical staff

Data Architecture Documentation Use Cases

Differing format types

Common elements

Use case name specified by a verb or verb phrase

End users identified by label “actor”

Section that identifies main steps performed

Extension or variation section describing alternate flows or actions

Sample Use Case Documentation

Data Architecture Documentation Data Flow Diagram (DFD)

A visual process model used to model the processes, flow, and transformation of data in a system.

Used to model “as-is” and “to-be” system processes

Provides the opportunity to assess differences in “as-is” and “to-be” systems

Data Architecture Documentation Data Flow Diagram (DFD)

Developed  from use cases or created directly from the results of requirements gathering

Shows a system’s functionality at a high level

Logical DFDs

Describe processes from a business view

Physical DFDs

Describe system technical details

Data Architecture Documentation Data Flow Diagram (DFD)

DFD components

External entity (EE)

A person, company, agency outside the organization or system under discussion (SuD)

Process

Any activity performed electronically or manually

Data flow (DF)

Any input to or output from processes or data stores

Data store (DS)

Organized collection of data, such as database or file

Data Architecture Documentation DFD Notation Styles

Data Architecture Documentation DFD Modeling

Consists of a set of hierarchical DFD diagrams

Sequentially breaks down a process to its most basic parts

Context diagram consists of the highest-named process or system and includes the EE and the data that flows from and to the process

Level 0 and successive diagrams provide specifics about the sub-processes composing the main process in the context diagram

DFD Context Diagram

DFD Level 0 Diagram

Data Architecture Documentation Data Model

Data model purpose

Describe the things about which an organization wishes to collect data

Convey this meaning to:

End users

System designers

Technical staff

Use as basis to design and construct actual system

Data Architecture Documentation Data Model

Entity Relationship Diagram (ERD)

One of the most common of data modeling methods

Used for modeling relational databases

Models entities, attributes, and relationships

Data Architecture Documentation Data Model

Data model includes

Entities

A person, place, thing, or event

Attributes

Describe an entity

Relationships among entities

Data Architecture Documentation Data Model

Types of data models:

Conceptual

Logical

Enterprise

Physical

Data Architecture Documentation Data Model

Conceptual data model

The highest representation

Includes entities in a business and the relationship among them

Does not contain attributes of entities

Precedes development of the logical data model

Data Architecture Documentation Data Model

Logical data model

A representation of the logical organization of the data, usually for one system or subject area of the business

Does not reference any technical details such as how the data are stored, indexed, retrieved, or manipulated

Data Architecture Documentation Data Model

Enterprise data model

A logical data model that is a representation of the logical organization of enterprise data showing overlaps between enterprise systems

Data Architecture Documentation Data Model

Physical data model

Represents how the data are physically stored in the database

Based on the logical data model

Includes the tables and columns and metadata such as data type and field length

Data Architecture Documentation Data Model Example

Database Structures

Flat file

Hierarchical

Network

Relational

Object-oriented

Database Structures

Flat file structure

First type of database structure

Files are not structurally related to each other

Create data redundancy, consistency, insertion, and update problems

Database Structures

Hierarchical structure

First appeared as a commercial product in the mid-1960s

Tree structure based on the concept of “parent” and “child” relationships

Strength is its ability to traverse a hierarchy very quickly for data retrieval

Random access to data across patients, non-routine, and ad hoc queries can be extremely slow

Database Structures

Network structure

Remedies problem of slow data across entities of hierarchical structure by allowing more than one parent table to share child tables

Drawback is that if the logical data model changes, the physical structure of the database is not easily modified

Database Structures

Relational structure

The most prominent architecture used today

First developed in 1960’s and based on relational algebra

Makes many improvements in data management over the flat file, hierarchical, and network models

Provides structure to establish relationship among files

Database Structures

Relational structure benefits

Enables quick access to data

Permits flexibility in changing database structure

Accommodates the use of complex queries to retrieve data

Ensures propagation of data changes throughout the database

Offers data integrity controls

Allows efficient modification and development of application programs

Provides standard query language (SQL)

Database Structures

Object Oriented (OO) Structure

Developed to deal with increasingly complex data types such as graphics, engineering designs, spatial, and audio-visual data

Combines the concepts of the hierarchical database and object-oriented programming

Combines the attributes (the data) and the programming code (methods) in an object

Benefits: Modularizes and permits reuse of the object by different parts of the system

Case tools

Data Architecture Documentation CASE Tools

Computer assisted software engineering (CASE) tools

Support documentation and communication aspects of the SDLC

Integrate tasks throughout the life cycle stages

Categories include visual aids, prototypes, data dictionary (DD) development, analysis, design, and code generation tools

Data Architecture Documentation CASE Tools

Upper CASE tools

Support the analysis phase

Such as DFDs, data process diagrams, use cases, logical ERDs

Lower CASE tools

Support design and implementation

Such as physical ERDs, screen designs, prototypes, and code generation

Data Architecture Documentation CASE Tools

Benefits

Reduced time to complete analysis and development tasks

Decreased analysis and developmental costs

Better documentation than manual processes

Disciplined development approach

Higher software quality

Improved communication among developers and other stakeholders

Shared project and system documentation repository

CASE Data Entry Screen Example

Data Architecture Documentation Data Dictionary

The central repository for information about

Tables, attributes, and relationships

Includes metadata such as:

Data definitions, default values, validation criteria, and messages

Used by analysts, programmers, and end users to understand the system

Strict naming conventions for tables, attributes, and relationships should be established

Applying DG to data architecture management

Data Architecture DG

Develop, update, and maintain data models and data model policies and standards

Define roles, responsibilities, and accountabilities for data architecture management

Develop, maintain, and evaluate policies and standards for requirements analysis

Develop and maintain data artifacts and standards

Develop and implement a quality control program and metrics for data architecture management