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CHAPTER 5. ANALYSIS PHASE OF BUSINESS SYSTEM DEVELOPMENT METHODOLOGY. INTRODUCTION . System Analysis – is a term that describes the early phases of systems development.
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CHAPTER 5 ANALYSIS PHASE OF BUSINESS SYSTEM DEVELOPMENT METHODOLOGY
INTRODUCTION • System Analysis – is a term that describes the early phases of systems development. • problem solving technique that decomposes a system into its component pieces for the purpose of studying how well those component parts work & interact to accomplish their purposes.
System analysis approaches • There are 4 system analysis approaches; • Model driven analysis approach • Accelerated analysis approach • Requirements discovery methods • Business process redesign methods
Model Driven Analysis Approaches • Emphasizes the drawing of pictorial system models to document & validate both existing & proposed system. • The system model becomes the blueprint for designing & constructing an improved system. • Example of software : VISIO Structures Analysis • Was one of the first formal approach for system analysis of business information system. • Used to either analyze an existing system, define business requirements for new system or both.
Model Driven Analysis Approaches Information Engineering • Model driven & data centered approach to plan, analyze & design information systems. • Consists of pictures that illustrate & synchronize the system’s data & processes. • Said to be data-centered paradigm because it emphasizes the study & requirement analysis of data requirements before those of the process & interface requirements. • This is based on the belief that data is a corporate resources that should be planned & managed.
Model Driven Analysis Approaches Object Oriented Analysis • Is a technique that integrates data & process concerns into constructs called objects. • Consists of pictures that illustrates the system’s objects from various perspectives such as structure & behaviour. • Unified Modeling Language (UML) provides a graphical syntax for an entire series of object models.
Accelerated Analysis Approaches • Emphasize the construction of prototypes by rapidly identifying business & user requirements for a new system. • Emphasizes the interface building blocks in the information system framework by constructing sample forms & reports. • Prototype – a small scale, incomplete but working sample of desired system.
Accelerated Analysis Approaches Discovery Prototyping • Uses rapid development technology to help users discover their business requirements by having them reach to quick-and- dirty implementation of those requirements. Rapid Architecture Analysis • An accelerated analysis approach that also builds a system models. • Attempts to derive system models from existing systems or discovery prototype. • It is made possible by reverse engineering technology that is included in many tools such as CASE & programming languages.
Accelerated Analysis Approaches • Reverse engineering technology reads the program code for an existing database, application program, user interface & automatically generates the equivalent system model. • The resulting system model can be further edited by system analyst & users to provide a blueprint for a new & improved system.
Requirement Discovery Methods • Includes those techniques to be used by system analyst to identify or extract system problems & solution requirements from the user community. Fact-finding Techniques • An essential skill for all system analysts. • Classical set of techniques used to collect information about system problems, opportunities, solution requirements & priorities.
Accelerated Analysis Approaches • Fact finding techniques; • Sampling of existing documentation, reports, forms, memos • Research of relevant literature, site visits • Observation on the current system & work environment • Questionnaires & surveys of the management & users • Interviews of the appropriate managers, users & technical staffs.
Business Process Redesign Methods • Business process redesign – the application of system analysis methods to the goal of dramatically changing & improving the fundamental business processes of an organization, independent of information technology. • Suitable for a study of existing business processes to identify problems & inefficiencies that is addressed in requirements for new / improved system.
The Preliminary Investigation Phase • Investigation is done by system analyst to study the systems request & recommend specific action. • The analyst gathers fact about the problem / opportunity, project scope & constraints, project benefits & estimated development time & cost. • The end product of the investigation is a report to the management.
Steps in the Preliminary Investigation Step 1: Understand the problem / opportunity Step 2: Define project scope & constraints Step 3: Performs fact-finding Step 4: Determine feasibility Step 5: Estimate development time & cost Step 6: Present result/recommendation to management
Steps in the Preliminary Investigation Step 1: Understand the problem / opportunity • System analyst might need to develop a business profile. • Analyst will need to understand & know how the modifications will affect the business operation or system even when it’s a small alteration. Step 2: Define the project scope & constraints • Means to define boundaries/extent of the project being as specific as possible. • Projects that expands gradually without specific authorization is called = project creep
Steps in the Preliminary Investigation • Types of constraints ; present, future, internal, external, mandatory & desirable. Step3: Perform fact-finding • Analyst will perform this step using various techniques such as; • Analyze organization charts – to understand how departments functions & identify the individual involved • Conduct interview – interviewing the identified individual. • Review current documentation – analyst should check whether the documentation received is accurate & complete • Observe operation – use statistic technique to check the frequency • Carry out a user survey – especially when it involves larger group.
Steps in the Preliminary Investigation Step4 : Determine feasibility • To determine economic feasibility. Step5 : Estimate time & cost • To determine cost & time the following need to be addressed: • What information needed & how to gather & analyze? • Source of information to use & the constraints to use it? • How many will be interviewed & how much time & cost for it. • How much cost to alayze the information gathered & prepare final report.
Steps in the Preliminary Investigation Step6 : present results & recommendations to management • If minor problem then recommendation is given without further analysis, but if the problem is big then further analysis is needed (development phase)
Problem Analysis Phase • Provides the analyst a better understanding of the problems, opportunities & directives that triggered the project. • The goal of this phase is to study & understand the problem domain well enough to analyze its problems, opportunities & constraints.
Steps in Problem Analysis Phase • Analyst must follow a series of steps: • Step 1 – study the problem domain • Step2 – analyze problems & opportunities • Step3 – analyze business process • Step4 – establish system improvement objectives • Step 5- update the project plan • Step 6 – present findings & recommendations to management
Steps in Problem Analysis Phase • Step 1 – study the problem domain • Attempts to learn about the current system • Step2 – analyze problems & opportunities • To perform this step, project team must work with system owners & system users • Cause & effect analysis is a technique in which problems are studied to determine their causes & effects.
Steps in Problem Analysis Phase • Step3 – analyze business process • Analyze business needs – to clearly define the business & system requirements. • Define business solution – IT experts define in the form of programs 7 databases, business people define in procedures to fulfill business mission. • Test business solution – evaluating whether the solution fulfills the business need. • Step4 – establish system improvement objectives • Any improvement to the system will be measured & constraints identified. Criteria for success measured in term of objectives
Steps in Problem Analysis Phase • Step 5 – update the project plan • This task is triggered by completion of the system improvement objectives. • Initial project plan = input, updated project plan = output • Step 6 – present findings / recommendations • This task is triggered by the completion of the updated project plan.
Requirements Analysis Phase • Defines the business requirements for a new system. • Final deliverables & milestones is to produce a business requirements statement that will fulfill the system improvement objectives.
Steps in Requirements Analysis Phase • Steps are as follows: • Step 1 – define requirements • Step2 – analyze functional requirements • Step3 – trace & complete requirements • Step4 – prioritize requirements • Step5 – update the project plan • Step6 – outgoing requirement management
Steps in Requirements Analysis Phase • Step1 : define requirements • A functional requirement – a description of activities & services a system must provide (input, output, stored data & processes) • Non functional requirement – description of other features, characteristics & constraints that define a satisfactory system (performance, budgets, cost) • Step2 : Analyze functional requirements • System modeling – graphical representation of concept or process that system developers can analyze, test & modify • Prototyping – creation of early working version of the information system or its components.
Steps in Requirements Analysis Phase • Step3 – Trace & complete requirements • Tracing each system model / prototype back to the functional requirement to ensure all functional requirements are fulfilled. • Step4 – prioritize requirements • Timeboxing – technique that delivers information system’s functionality & requirements through versioning.
Steps in Requirements Analysis Phase • Step5 : update the project plan • The completed business requirements statement completes the task, as well as the requirement analysis phase. • Step6 : ongoing requirement management • Requirement management defines a process for everyone involved in the system development that specifies how changes are to be requested & documented, how to be logged & tracked, etc
Decision Analysis Phase • Identifies candidate solutions, analyses those candidate solutions & recommends a target system that will be designed, constructed & implemented.
Steps in Decision Analysis Phase • Steps are as follows ; • Step1 – identify candidate solutions • Step2 – analyze candidate solutions • Step3 – compare candidate solutions • Step4 – update the project plan • Step5 – recommend a system solution
Steps in Decision Analysis Phase • Step 1: identify candidate solution • System owners & users may not be directly involved in the task, but they may contribute ideas & opinions that start the task. • Step2: analyze candidate solution • Each candidate solution must be analyzed for feasibility. • 4 criteria: • Technical feasibility • Operational feasibility • Economic feasibility • Schedule feasibility
Steps in Decision Analysis Phase • Step3 : Compare candidate solution • The deliverables of this task is the solutions to be recommended. If more than one solution is recommended, priorities should be established. • Step4 : update the project plan • System analyst are adjusting scope accordingly, so based on the solution recommended, analyst should re-evaluate project scope & update project plan accordingly
Steps in Decision Analysis Phase • Step6 : Recommend a solution • This task is triggered by the completion of the updated project plan.