1 architecture mis 5003. 2 architecture components and the relationships among them. zprogram...
Post on 19-Dec-2015
216 views
TRANSCRIPT
1
Architecture
MIS 5003
2
Architecture
Components and the relationships among them.
Program architectureApplication architectureEnterprise system architecture
3
Program Architecture
A part of the system design processDefine sub-programsDefine program modulesDefine data storesSpecify the calling sequences
e.g. System flow charts & Functional Hierarchy Diagrams
4
Application Architecture
Structure of a particular application.Databases and program componentsDevices and operating environments on
which these runCommunication links among the devices
Application architecture must take into account the enterprise architecture and its current load.
5
Enterprise Architecture
Structure of clients, servers, operating environments, networks and security used to support the enterprise applications.
Usually too expensive to be justified by a single application
Generally defines standards to which applications must adhere
6
What is Enterprise System Architecture?
Narrow - Hardware, Operating System and other System Software, DBMS & Network
Broad - Add: Application Programs, Design Tools, Physical Layout, Policies and Procedures
7
Principles for the Ideal Architecture
Open, High Performance/Cost Immediate AvailabilityInfinitely ScaleableCompletely Secure, Failure FreeInexpensive, Rapid ChangeHigh Level of User ControlLittle or no Training Required
8
The ISSUE for this Class
How does a person make “good” decisions in selecting architectures or components
9
Different Views
Business ViewReach, range, response & risk
Conceptual ViewNodes, application mix, performance
parameters & security planDesign View
Network design, server specifications, operating systems and middleware, program decomposition, segmentation and firewalls
10
Business View
Reach: locations for delivery
Range: application mix
Response: deferred, real time, interactive
Risk: threat*success*cost
11
Conceptual View
Translation of user needs into technical specifications.
Functionality at each nodeData and process demands for the
systemDialog expectations and processing
turnaround needsSecurity objectives
12
Design View
Distribution of functions across nodesLocation of data and access proceduresNode specifications (or specifications of
existing nodes)Location of firewalls and use of added
security such as encryptionLink specifications and interconnection
design
13
Base Architecture
Mainframes -- few new applications; used mostly for legacy ones
Client/Server -- most new applications; main direction for next several years
NetCentric -- important new area; will it take over some or all
Combinations -- case for most systems
14
Mainframe Architecture -- 1990
Proprietary $100,000/MIPSYears to DeliverDifficult to ScaleChange DifficultRemote Users Works Well!
15
Mainframe Architecture in 2000
$2,000 per MIPSOpen architectureNow a Network Server as wellShort Delivery time Excellent operating systems &
supportIncreased scalabilityLarge set of existing programs
16
Distributed System Characteristics - 1999
Open, <$100/MIPSShort AvailabilityGood ScalabilityMore User ControlMore Likely to FailCostly Training Costly to MaintainPolicy control Issue
17
Distributed Architectures
ServerServer
ClientClient
MainframeMainframeSystemsSystems
Stand AloneStand AlonePCPC
FatFatClientClient
ThinThinClientClient
Amount of WorkAmount of Work
Netcentric
18
TelecommunicationsEssential Link for Distributed
SystemsArea and Control
Local (LAN) - nearby, private Wide (WAN) - further away, public
Specifications - capacity or speedTechnology
19
NetCentric Systems
Intranets - Standard Browser & Protocol (TCP/IP)
Central Control of Intranet, some Applications, some Servers
Fast Approach to a Global System
Allows Local Autonomy
22
Electronic Commerce (EDI)
Issues: Cost, Elapsed Time, Access
Basic EDI-- electronic transactions, data flows, reports
Electronic markets and productsElectronic OutsourcingElectronic Virtual Firms
23
Electronic Commerce (B2C)
Issues: how do we use it.Reliability, accessibility, security.Electronic effects on traditional brick
and mortar business.Advertisement, electronic
registration, transaction processing, customer relationship management.
24
Broad Issues For Architectures
Business FunctionsCompany Preferences InteroperabilitySecurityReliability / AvailabilitySystem Management Tools Cost / Effectiveness
25
Company Culture
IS Priority of the Responsible ManagerPerceived Performance of Current IS Risk & Failure ToleranceChange ToleranceDesire to LeadExperience BaseSkills Base
26
Base Technologies I
High Performance/Cost, multi-chip Servers
Relational &/or Object DBMSFast, switched Ethernet, RoutersInternet II, faster, lower cost WANSElectronic signatures, high security
27
Base Technologies II
Multiple Architecture StructuresHigh Levels of CompetitionHigh Innovation RatesIncreasing Business and
Strategic Importance of IS Increasing IS visibility
28
Security in Distributed Systems
Passwords - one or multipleAuthenticationAccess Control ListsFirewallsEncryption & Electronic SignaturesSecurity Failure DetectionDamage Control and Correction
29
Availability Protection
Physical Control / ProtectionShadow Systems / LocationsMirror DatabasesRAID - Redundant Arrays of
Inexpensive DisksFault Tolerant ServersSystem Backups - Secure Storage
30
Vendors & Outsourcing
General Opinion -- consultants, other users, open literature
Direct Prior ExperiencesSpecifics-- Warranty Experience,
Customer Service, Response Time, Update Policy, Industry Position, Longevity
31
Future Forecasts
TechnologiesVendorsIS SkillsBusiness
FunctionsMarkets
You have no future!
CIO
32
Futures I
Multiple ArchitecturesWidespread Electronic CommerceIncreased Competition - Downsize,
Reorganize, Merge, FailSystem Design - Still Difficult,
Expensive and High Risk
33
Futures II
Continue New Technologies - Fast/Large everything, Voice, non-silicon processors/storage
Hardware Cost/Performance Telecommunications improvementsReduce labor cost - - CASE,
Package Programs, Outsourcing.
34
Technology Assessment
Winning technologies generally have:Low costEarly introductionGood enough performanceMarket share
Most technology innovations have evolved into one or two dominant products over time.