IT ARCHITECTURE © Holmes Miller 1999

BUILDING METAPHOR 3CUSTOMER’S CONCERN Has vision about building that will meet needs and desires 3ARCHITECT’S CONCERN Translates the vision into a plan to construct the building

ANALOGOUS TO A BUILDING 3GENERAL MANAGER’S CONCERN Applications to use, data that will be accessible, and communications that will be possible 3IT ARCHITECT’S CONCERN Desired system functions and appropriate technology

COMPONENTS 3Hardware 3Software 3Data 3Communications links

HARDWARE COMPONENTS 3Central processing unit 3Primary storage 3Secondary storage 3Input devices 3Output devices 3Telecommunications links

SOFTWARE COMPONENTS 3Operating system software 3Application software

DATABASES Database hierarchy is: 3Bit 3Byte 3Field 3Record 3File 3Database

DATABASE ORGANIZATION 3SEQUENTIAL ORGANIZATION Tape oriented - one file follows another 3DIRECT ORGANIZATION Disk oriented - can be accessed without regard to physical sequence

DATABASE MANAGEMENT SYSTEMS 3STORED IN WAY FOR DIFFERENT BUSINESSES TO ACCESS THE SAME DATA 3COMPONENTS Data definition language Database management software Data dictionary

DATABASE TYPES 3HIERARCHIAL One to Many 3NETWORK Many to Many 3RELATIONAL Use Table format

DATABASE PROS & CONS 3HIERARCHIAL High efficiency - Low flexibility 3NETWORK Medium efficiency - Medium flexibility 3RELATIONAL Low efficiency - High flexibility

DATABASE TRENDS 3DISTRIBUTED PROCESSING Multiple systems connected via a network 3DISTRIBUTED DATABASE Data physically stored in more than one location 3DATA WAREHOUSE Consolidate current & historical information - - Data Mining!

DATABASE TRENDS 3DATA WAREHOUSE: Organization’s electronic library stores consolidated current & historic data for management reporting & analysis 3DATA MART: Small data warehouse for special function, e.G., Focused marketing based on customer info

COMPONENTS OF DATA WAREHOUSE

DATABASE TRENDS 3ON-LINE ANALYTICAL PROCESSING (OLAP): ability to manipulate, analyze large volumes of data from multiple perspectives 3LINKING DATABASES TO THE WEB

ELEMENTS OF DATABASE ENVIRONMENT DATABASE MANAGEMENT SYSTEM DATA ADMINISTRATION DATABASE TECHNO LOGY & MANAGEMENT USERS DATA PLANNING & MODELING METHODOLOGY

COMMUNICATIONS LINKS 3NETWORKS Hardware and software that permits computer-computer or computer-peripheral communication 3COMMUNICATIONS DEVICES Hardware devices to control communication in a computer system

DEVELOPING AN ARCHITECTURE SOME ISSUES 3On-going business process 3Central vs. local control 3Standards 3Vendors 3Rules & policies

DEVELOPING AN ARCHITECTURE OVERALL PROCEDURE 3Where are we now? 3Where do we want to be? 3How should we get there? TWO APPROACHES 3Evolutionary 3Revolutionary

DEVELOPING AN ARCHITECTURE FIVE STEPS 3Articulate the business strategy and architecture implications 3Baseline the company architecture 3Determine key architecture questions 3Design the blueprint 3Initiate the architecture plan

CAPITAL BUDGETING MODELS LIMITATIONS: 3Assume all relevant alternatives have been examined; cost & benefits can be expressed as $$ 3Ignore intangible benefits UNDERSTANDING BUSINESS VALUE OF INFO SYSTEMS

Capital Budget: Process of analyzing, selecting capital expenditures 3Payback method 3Return on investment 3Cost-benefit ratio 3Net present value 3Profitability index 3Internal rate of return

Costs: 3Hardware 3Software 3Services 3Personnel Costs & Benefits:

Tangible benefit: 3Increased productivity 3Low operating costs 3Reduced work force 3Lower computer expenses 3Lower vendor costs 3Lower clerical/professional costs 3Reduced growth of expenses 3Reduced facility costs Costs & Benefits:

Intangible benefit: 3Improved asset use; resource control; planning 3Increased flexibility 3More timely information 3Increased learning 3Attain legal requirements 3Enhanced employee goodwill, job satisfaction, decision making, operations 3Higher client satisfaction 3Better corporate image Costs & Benefits:

Portfolio Analysis: Analysis of potential applications to determine risks & benefits 3Determine desirable features, acceptable risks of required system 3Generate portfolio of characteristics, risks for each alternative 3Scoring model