INFO425: Systems Design INFORMATION SYSTEMS @ X Finalizing Scope (functions/level of automation) Finalizing scope in terms of functions and level of

INFO425: Systems DesignINFO425: Systems Design

INFORMATION SYSTEMS @ XINFORMATION SYSTEMS @ X

Finalizing Scope (functions/level of Finalizing Scope (functions/level of automation)automation)

Finalizing scope in terms of functions and level of Finalizing scope in terms of functions and level of automation for each function overlaps with and automation for each function overlaps with and requires information from:requires information from:

Defining target deployment environmentDefining target deployment environment Defining implementation alternativesDefining implementation alternatives

> e.g., build vs. buye.g., build vs. buy

General Approach for including/excluding functions:General Approach for including/excluding functions: Functions deemed mandatory are in scope.Functions deemed mandatory are in scope. Include as many important functions as budget and schedule allowInclude as many important functions as budget and schedule allow Desirable features: delay to later ‘release’ of systemDesirable features: delay to later ‘release’ of system

Strategic plan:Strategic plan: Often, genesis of a new system is organization’s strategic planOften, genesis of a new system is organization’s strategic plan Functions that align with strategic plan typically get included in scopeFunctions that align with strategic plan typically get included in scope



Finalizing Scope (functions/level of Finalizing Scope (functions/level of automation)automation)

Need to revisit feasibility analysis. Now have much more Need to revisit feasibility analysis. Now have much more information to work with.information to work with.

Economic feasibilityEconomic feasibility What set of functions give us an optimal return on investment?What set of functions give us an optimal return on investment? What set of functions can we afford?What set of functions can we afford?

Schedule and resource feasibilitySchedule and resource feasibility What can be implemented in time available?What can be implemented in time available? What can be implemented given human and other resources?What can be implemented given human and other resources?

Technological feasibilityTechnological feasibility What can be practically implemented given state of technology and What can be practically implemented given state of technology and

organizations knowledge and experience?organizations knowledge and experience? Operational, organizational, and cultural feasibilityOperational, organizational, and cultural feasibility

What can our organization handle/accept?What can our organization handle/accept? How much change is required?How much change is required?



Application Deployment EnvironmentApplication Deployment Environment

What is the technical environment in which system will be What is the technical environment in which system will be implemented?implemented?

Deployment environment consists primarily of:Deployment environment consists primarily of: HardwareHardware Networks Networks System softwareSystem software Development softwareDevelopment software Development methodology and toolsDevelopment methodology and tools

Technical requirements define constraints regarding Technical requirements define constraints regarding deployment environmentdeployment environment

Organization’s current environment/standards typically drive Organization’s current environment/standards typically drive deployment options deployment options



Range of Application TypesRange of Application Types

Stand-alone applications on mini- and personal Stand-alone applications on mini- and personal computerscomputers

Online interactive applicationsOnline interactive applications

Distributed applicationsDistributed applications

Web-based applicationsWeb-based applications



Hardware, System Software, and NetworksHardware, System Software, and Networks

Computers range from handheld to super Computers range from handheld to super computerscomputers

Operating systems range from Windows to UnixOperating systems range from Windows to Unix Database management systems range from Oracle Database management systems range from Oracle

to SQL Server to IBM DB2to SQL Server to IBM DB2 Software components and standards range from Software components and standards range from

Java 2 Enterprise (J2EE) to Microsoft .NETJava 2 Enterprise (J2EE) to Microsoft .NET Web servers range from IIS to ApacheWeb servers range from IIS to Apache



Deployment Environment Characteristics to Deployment Environment Characteristics to ConsiderConsider

Compatibility with technical requirements:Compatibility with technical requirements: Volume of transactions, location of users, etc.Volume of transactions, location of users, etc.

Compatibility among hardware and system Compatibility among hardware and system softwaresoftware

Required interfaces to external systemsRequired interfaces to external systems Conformity with IT strategic plan and architecture Conformity with IT strategic plan and architecture

plansplans Cost and scheduleCost and schedule



Development ToolsDevelopment Tools

Development environment Development environment –– programming programming languages, CASE tools, and other software used to languages, CASE tools, and other software used to develop application softwaredevelop application software

Java and Visual Studio .NET are examplesJava and Visual Studio .NET are examples

Application deployment environment decisions Application deployment environment decisions limit development tool choiceslimit development tool choices

Operating system environmentOperating system environment

Database management system (DBMS)Database management system (DBMS)

Distributed software standardDistributed software standard



Development and System Software Development and System Software EnvironmentsEnvironments

Consists of standards and tools used in an organization to Consists of standards and tools used in an organization to develop systemsdevelop systems

Important considerationsImportant considerations Language environment and expertiseLanguage environment and expertise

> Java, C, etc,Java, C, etc, Existing CASE tools and methodologiesExisting CASE tools and methodologies

> RUP and Rose, Information EngineeringRUP and Rose, Information Engineering Required interfaces to other systemsRequired interfaces to other systems Operating system environmentOperating system environment

> Unix, Linux, OS390, NTUnix, Linux, OS390, NT Database management system environmentDatabase management system environment

> Oracle, DB2, SQL ServerOracle, DB2, SQL Server



Choosing Implementation AlternativesChoosing Implementation Alternatives

Many variations on obtaining a system Many variations on obtaining a system Facilities management solutionsFacilities management solutions Packaged, turnkey, ERP software systemsPackaged, turnkey, ERP software systems Custom software developmentCustom software development In-house developmentIn-house development



Implementation AlternativesImplementation Alternatives

ASPsASPs

Salesforce. Salesforce. comcom

MySAP.comMySAP.com

ERP ERP

SAPSAP

PeopleSoft PeopleSoft

Off the shelf Off the shelf packagespackages

Simply Simply AccountingAccounting

We build, consultants build or We build, consultants build or blended approachblended approach



IdentifyingIdentifying Criteria for SelectionCriteria for Selection

Comparisons difficultComparisons difficult Different proposed systems have strengths in different Different proposed systems have strengths in different

areasareas Need a consistent framework for comparison of Need a consistent framework for comparison of

alternativesalternatives CriteriaCriteria WeightsWeights ScoresScores

Three areas to considerThree areas to consider General requirementsGeneral requirements Functional requirementsFunctional requirements Technical requirementsTechnical requirements



Evaluation FrameworkEvaluation Framework

Evaluation Evaluation CriteriaCriteria

Weight – Weight – importance of importance of

criteria vs other criteria vs other criteriacriteria

Alternatives Alternatives consideredconsidered

ScoreScore Score * Score * WeightWeight

TotalTotal

4949

TotalTotal

4242



EVALUATION FRAMEWORK (EXPANDED)EVALUATION FRAMEWORK (EXPANDED)



General RequirementsGeneral Requirements

General requirements include considerations that General requirements include considerations that are important but not directly associated with the are important but not directly associated with the computer system itself. computer system itself.

Related to feasibility assessment – alternative Related to feasibility assessment – alternative must be feasible to be chosenmust be feasible to be chosen

General requirements examples:General requirements examples: Performance record of the providerPerformance record of the provider Level of technical support from the providerLevel of technical support from the provider Warranties and support services (from outside vendor) Warranties and support services (from outside vendor) Availability of experienced staffAvailability of experienced staff Development costDevelopment cost Expected value of benefitsExpected value of benefits Length of time (schedule) until deploymentLength of time (schedule) until deployment Requirements for internal expertiseRequirements for internal expertise Organizational impacts (retraining, skill levels)Organizational impacts (retraining, skill levels)



Technical RequirementsTechnical Requirements

Constraints under which system must operateConstraints under which system must operate Defined by technical requirements identified Defined by technical requirements identified

during information gatheringduring information gathering Categories:Categories:

Performance (response time/throughput, etc)Performance (response time/throughput, etc) Security and ControlSecurity and Control User interface (ease of use, etc.)User interface (ease of use, etc.) Service (number/location of users to be supported)Service (number/location of users to be supported) Operating environmentOperating environment etc.etc.



Functional RequirementsFunctional Requirements

Need to evaluate alternatives based on how well Need to evaluate alternatives based on how well they meet functional requirements.they meet functional requirements.

Use expanded event tableUse expanded event table



Evaluating Functional RequirementsEvaluating Functional Requirements



Evaluating Technical RequirementsEvaluating Technical Requirements



Making the SelectionMaking the Selection

After rating alternatives, choice can be madeAfter rating alternatives, choice can be made Scores are tabulated and comparedScores are tabulated and compared



Partial Matrix of General RequirementsPartial Matrix of General Requirements

Systems Analysis and Design in a Changing World, 5th Edition

20

Figure 8-7



Partial Matrix of Functional RequirementsPartial Matrix of Functional Requirements


21

Figure 8-8



Partial Matrix of Technical RequirementsPartial Matrix of Technical Requirements


22

Figure 8-9



Contracting with VendorsContracting with Vendors

Generate a Request for ProposalGenerate a Request for Proposal



Presenting Results and Making DecisionsPresenting Results and Making Decisions

Compile, organize, and present the alternatives and Compile, organize, and present the alternatives and critical issues in an easy-to-understand but complete critical issues in an easy-to-understand but complete mannermanner

Final choice generally made by executive steering Final choice generally made by executive steering committeecommittee

Format of documentation and presentation style varies Format of documentation and presentation style varies with organizationwith organization

Documents

INFO425: Systems Design INFORMATION SYSTEMS @ X Finalizing Scope (functions/level of automation) Finalizing scope in terms of functions and level of