INFO425: System Design INFORMATION SYSTEMS @ X Chapter 8 Evaluating Alternatives for Requirements,...

INFO425: System DesignINFO425: System Design

INFORMATION SYSTEMS @ XINFORMATION SYSTEMS @ X

Chapter 8Chapter 8

Evaluating Alternatives for Evaluating Alternatives for Requirements, Environment, and Requirements, Environment, and

ImplementationImplementationPart 1Part 1



ObjectivesObjectives

Describe process for packaging/prioritizing system Describe process for packaging/prioritizing system requirements based on the desired system scope and requirements based on the desired system scope and level of automation for the new systemlevel of automation for the new system

Describe the strategic decisions that determine the target Describe the strategic decisions that determine the target deployment environment and the design approach for the deployment environment and the design approach for the new systemnew system

Determine alternative approaches for system Determine alternative approaches for system developmentdevelopment

Evaluate and select a development approach based on Evaluate and select a development approach based on the needs and resources of the organizationthe needs and resources of the organization



OverviewOverview

Last three activities of analysisLast three activities of analysis Prioritize systems requirementsPrioritize systems requirements Generate and evaluate alternativesGenerate and evaluate alternatives Review recommendation with managementReview recommendation with management

Refocus project directionRefocus project direction Transition from discovery and analysis to solutions and Transition from discovery and analysis to solutions and

designdesign Set direction for design and implementation of solution Set direction for design and implementation of solution

systemsystem



System Analysis ActivitiesSystem Analysis Activities

Final three steps overlap with initial steps and done Final three steps overlap with initial steps and done iterativelyiteratively

Steps:Steps: Define priority of each event (function)Define priority of each event (function) Define the level of automation for each eventDefine the level of automation for each event Define the deployment environment (hardware, operating system, Define the deployment environment (hardware, operating system,

network)network) Identify design alternatives (e.g., custom development vs. Identify design alternatives (e.g., custom development vs.

package)package) Evaluate design alternativesEvaluate design alternatives Select alternative and present to managementSelect alternative and present to management



Project Management PerspectiveProject Management Perspective

TimeTimeCostCostQualityQuality

Human resourcesHuman resourcesProcurementProcurementCommunicationsCommunicationsRiskRisk

The final activities of the Systems Analysis phase are The final activities of the Systems Analysis phase are largely (but not entirely) project management activitieslargely (but not entirely) project management activitiesOverall goal is to precisely define scope and to specify Overall goal is to precisely define scope and to specify how system will be implemented. This allows the project how system will be implemented. This allows the project manager to quantify the following dimensions of the manager to quantify the following dimensions of the project:project:



Deciding on Scope and Level of Deciding on Scope and Level of AutomationAutomation

Scope determines which business functions (events) will Scope determines which business functions (events) will be included in systembe included in system

Level of automation is how much automated computer Level of automation is how much automated computer support exists for functions included in scopesupport exists for functions included in scope

Aim is to precisely define functions in scope and level of Aim is to precisely define functions in scope and level of automation for each function to avoid automation for each function to avoid scope creepscope creep

Requests for addition of system functions after requirements have been defined Requests for addition of system functions after requirements have been defined and decision has been madeand decision has been made

To avoid, formalize the processTo avoid, formalize the process Get key stakeholders to participate and sign offGet key stakeholders to participate and sign off



Prioritizing RequirementsPrioritizing Requirements

Assume that Event = FunctionAssume that Event = FunctionUse an expanded Event TableUse an expanded Event TableTypically, priority is defined when Event table is built, then Typically, priority is defined when Event table is built, then refined refined Priority: Mandatory, Important, DesirablePriority: Mandatory, Important, Desirable

Level of AutomationLevel of Automation

Event/FunctionEvent/Function PriorityPriority LowLow MediumMedium HighHigh

Schedule a course sectionSchedule a course section MandatoryMandatory

Enroll in CourseEnroll in Course MandatoryMandatory

Provide student Provide student suggested curriculum for suggested curriculum for upcoming academic yearupcoming academic year

DesirableDesirable

Generate student Generate student timetabletimetable

ImportantImportant



Defining Level of AutomationDefining Level of Automation

HighHigh> System takes over processing of business function … does most of the System takes over processing of business function … does most of the

work …. Applies business logic / ruleswork …. Applies business logic / rules> Ask the question: how should this function be done ideallyAsk the question: how should this function be done ideally

MediumMedium> Midrange point which combines features from low and high alternativesMidrange point which combines features from low and high alternatives

Low Low > Simple computer records keepingSimple computer records keeping> Often involves automating existing, manual tasksOften involves automating existing, manual tasks



Provide student Provide student suggested suggested curriculum for curriculum for upcoming academic upcoming academic yearyear

DesirableDesirable Generate printout Generate printout based on based on program, year program, year and courses and courses takentaken

Create tentative Create tentative schedule for year, schedule for year, online, prompt student online, prompt student to confirm/change as to confirm/change as requiredrequired

Medium + generate Medium + generate and email timetable and email timetable to studentto student



RMO Customer Support System Functions RMO Customer Support System Functions



Exercise – Student RegistrationExercise – Student Registration



Schedule a course Schedule a course sectionsection

MandatoryMandatory

Enroll in CourseEnroll in Course MandatoryMandatory

Generate student Generate student timetabletimetable

ImportantImportant

Define potential levels of automation for each functionDefine potential levels of automation for each function

INFO425: System Design INFORMATION SYSTEMS @ X Chapter 8 Evaluating Alternatives for Requirements,...

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