SummaryA system analyst solves business problems using information systems technology

Problem solving means looking into business problem in great detail, completely understanding problem, and choosing best solution

Information system development is much more than writing programs

System – a collection of interrelated components functioning together to achieve an outcome.Information system outcome – solution to a business problemInformation systems, subsystems and components interact with and include hardware, software, inputs, outputs, data, people, and proceduresSystem analyst has a broad knowledge and variety of skills, including technical business and peopleIntegrity and ethical behaviour are crucial to success for the analystSystems analyst encounters a variety of rapidly changing technologiesSystems analyst works on strategic plans and then system development projects

Analyst's Approach to problem solvingResearch and understand the problemVerify benefits of solving problem outweigh the costsDefine the requirements for solving the problemDevelop a set of possible solutions(alternatives)Decide which is best and recommendedDefine the details of the chosen solutionImplement the solutionMonitor to ensure the desired results

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SummarySystem development projects are organized around the systems development life cycle(SDLC)

Some projects use a predictive approach to the SDLC and others use a more adaptive approach to SDLC

SDLC phases include project planning analysis, design, implementation, and support.

In practice, phases overlap and projects contain many iterations of analysis, design, and implementation.

Models, techniques, and tools make up a system development methodology

System development methodology provides guidelines to complete every activity in the SDLC

System development methodologies are based on traditional approach or object-oriented approach

Current trends include: Extreme programming(XP), unified process(UP), and scrum

Visual modelling tools are designed to help analysts complete system development tasks.

Analyst as a project Manager

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SummaryAnalysis phase activitiesGather informationDefine system requirementsPrioritize requirementsPrototype for feasibility and discoveryGenerate and evaluate alternativesReview recommendations with managementBPRand ZachmanFrameworkcan help with the analysis phase activities

Summary (continued)Gathering system requirementsFunctional and nonfunctionalWork with various stakeholders (users, clients, technical staff)What kind of information do I need?What are the business processes and operations?How are the business processes performed?What are the information requirements?Summary (continued)Primary information-gathering techniquesReview existing reports, forms, and procedure descriptionsConduct interviews and discussions with usersObserve and document business processesBuild prototype working modelsDistribute and collect questionnairesConduct JAD sessionsResearch vendor solutions

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SummaryAnalysis phase - defines system requirementsModels created to further learning process, reduce complexity, communicate with team members, and document requirementsKey early step in modelling is to identify and list

Use cases (activities) are identified from user goals and business events that trigger elementary business processesBusiness events are memorable, can be described, and occur at a specific time and placeExternal events, temporal events, and state eventsEvent table records event, trigger, source, use case, response, and destinationA catalogue of information about each use case

Things are what user deals with and system remembers, such as customer placing an orderTraditional approach uses entity-relationship diagrams (ERD) for data entities, attributes of data entities, and relationships between entitiesObject-oriented approach uses UML class diagrams for classes, attributes, methods of class, and associations among classes

SummaryData flow diagrams are used in combination with event table and entity relationship diagram to model system requirementsDFDs model system as set of processes, data flows, external agents, and data storesDFDs easy to read - graphically represent key features of system using small set of symbolsMany types of DFDs - context diagrams, DFD fragments, subsystem DFDs, event-partitioned DFDs, and detailed process DFDs.Each process, data flow, and data store requires detailed definitionAnalysts may define processes as structured English process specifications, decision tables, decision trees, or detail process DFDsDetailed process decomposition DFDs used when internal process complexity is great.Data flows are defined by component data elements and their internal structure

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SummaryObject oriented approach has complete set of diagrams that define system requirements

Domain model class diagram(chapter 5)Use case diagrams(Chapter 7)Use case detailed models, either descriptive formats or activity diagrams(5 and 7)System sequence diagrams (7)State machine diagrams(chap 7)

Requirements specified using following models

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SummaryThese activities are primarily project manager responsibilities with support from project teamFocus of project changes from discovering requirements to developing solution systemPrioritize requirements based on scope and level of automationScope of new system determines functions it will supportLevel of automation is a measure of how automated the selected functions will beApplication deployment environmentComputer hardware, systems software, and networks in which new system will operateDetermines constraints imposed on system development alternativesAnalyst must define environment to matchApplication requirementsOrganization’s strategic application plansOrganization’s technology architecture plansDetermine what alternatives are possible for developing solutionImplementation alternatives includeBuilding system in-houseBuying packaged or turnkey solutionContracting with developer to build system (outsource)Develop recommendations and present to management to make funding decisions

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Summary

DFD is enhanced by adding system boundaryDesigner describes processes within each DFD boundary using one or more structure charts

For traditional structured approach to systems design, primary input is data flow diagram

Transaction analysis –multiple transaction typesTransform analysis –single transaction from input to output

Structure charts developed using

Modules will be clearly identified by layerStructure chart may be decomposed if layers execute on multiple systems

Structure charts may be based on three-layer architecture

System flowcharts to show data movementModule pseudocodeto describe internal logic of structure chart module

Structured design may also include

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Summary

Domain class diagrams are transformed into design class diagramsSequence diagrams are extensions of system sequence diagrams(SSDs)

Systems design is driven by use cases, design class diagrams, and sequence diagrams

Capture method signaturesShow navigation visibility

System sequence Diagrams

Summary

Domain class diagrams are transformed into design class diagramsSequence diagrams are extensions of system sequence diagrams (SSDs)

Systems design is driven by use cases, design class diagrams, and sequence diagrams

Capture method signaturesShow Navigation Visibility

System sequence Diagrams

Package Diagrams show subsystem organization and dependencies

Use case controller (MVC pattern)AdapterFactory and singletonObserver

Design patterns are useful solutions to standard programming problems

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SummaryAdaptive development methodologiesUnified Process (UP)

Flexible in an unpredictable business worldAgile modeling and agile development

Tests are written first, programmers work in pairsEXTREME programming

Defines a specific goal that can be completed within 4 weeksScrum

Provides techniques for larger organizations to intergrate all software and all software development across the entire enterprise

Model Driven Architecture

Object frameworks provide a means of reusing existing software through inheritanceComponents are units of reusable executable code that behaves as distributed objects.

Software reuse is a fundamental approach to rapid development

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Automation boundary: the boundary between the scale of human work and machine work

What does a Human Resource Management system support? Employees, clients, customers, etc

Description of the integrated IS of business is?

Best approach when exact requirements of system/users not know? Adaptive approach

The approach that completes a system in one or more iterations is called adaptive development

Structured programming constructs?Sequences, decisions, interaction.

What kind of skills should an Analyst have?Apart from tech skills, should also have the business skills, and people skills

Main components of a strategic plan?

Can the two main system development approaches be mixed? Example?No problem mixing object orientated and traditional, but linking them is hard

Name one best practice promoted by the unified process: work interactively. Also check quality

Name a critical factor in the acceptance of a system nowadays? The user interface, graphic

How many critical paths in a project?Any number, depending on the project

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What is a critical component for the user acceptance of a system: the Gooie part

What is the most important/critical component of a system modelling and design tool? The central repository

What is the main task of a help desk? Customer support

What kind of human resources training is required there? People skills

What is the critical path of a project? The path that contains the tasks that take the longest time to complete (how much time it'll take for the project to be done

Can there be more such paths? Yes

What is the slack time of an activity? The extra time to finish the task

What is PERT? Program Evaluation Review Technique (optimistic, pessimistic, realistic/6 = estimated time)

What is a model? Representation of reality (simplified)

What is a methodology? Methods, models and tools

What is SDLC and what could spiral SDLC be? System Development Life Cycle, The phases of the system to operate, etc. Spiral: Method where you do things again and again (repetatiiiiiiiiive bitches) aka repetitive life cycle(they keep going back through the same iterations, to keep refining the system)

What SDLC approach is used when the exact requirements of a system are not known/can change significantly? Adaptive

What are the basic structured programming constructs? Sequence, cycle, decision.

What is the object oriented design approach? Approaches everything as an object, and shows how the object interacts with the design

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What are the functional system requirements?What the system has to do

How about non functional system requirements?Tech, performance, user requirements

What are some types of models used in system analysis and designMathematical, descriptive, and graphical

Difference between logical and physical modelsLogical involves describing, planning, etc, while physical is actually working on it

What are typical stakeholders types?Users, suppliers, supporters

What is a workflow? Steps you have to undertakeWhat is a common document for this: activity model

What is a swimlane in an activity model?Keepings yourself to your lane of activity

What are synchronisation bars and when are they used.Used to synchronise activities

What are use cases?Things that the system does, in response to user action

How are use cases discovered?Asking the user questions

What does C.R.U.D.Create, Read, Update, and delete

What is an actor, how about a scenarioActor - something or someone who uses the systemScenario - particular set of steps

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A place on the project schedule that indicates a specific completion point is called a mile stone

Each class of things in a hierarchy can have a more general class above it called a Superclass

Each class of things in a hierarchy can have a specific classes below it called a subclass

A use case postcondition is a set of statements that is true...when? Objectives that should be true after the project is over

What is JAD, and what is it used for?Joint Application Design, to share ideas and brainstorm - deals with requirements

What do you call a unique path in a use case?Scenario

What is cardinality? Number of … between objectives

What is an associative class? A class associated to another class

What is a miracle in traditional approach? Giving an output with no inputs

What is a DFD and what is it used for?Data flow diagramWhat is a source in a dfd, how about a sinkSource gives data, sink takes data

What is DFD balancing?

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A place where data is held for access by one or more processes is a data store1)Processes with data elements created out of nothing is called a miracle2)What is an actor in OO SAD? Something or someone using the system3)What represents the [ and ] symbols in a system sequence diagrams? Guard condition4)Why are names underlined in a system sequence diagram? Cus their objects5)

6)How do we represent actors in a use case diagram?7)What are the dashed vertical lines in a sequence diagram? time8)What does a state transition diagram show? States of objects9)What are horizontal bars used for in activity diagrams? syncbars10)How many classes in a system sequence diagram? None11)how is repetition shown in a system sequence diagram? Have arrows returning to their source12)

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What in as intranet:Private network (can have a wide area network)

What is an extranet:Public network

What is a client server architecture?(causes all sorts of problems, whatever it is)

What are the 4 layers in a client server architecture?Presentation, logic, and storage

Which layer contains the main processing preformed by the system? The logic/business

Which layer is the most important for user acceptance of the system?Presentation

How is the system represented in a system sequence diagram?As an object

What are the dashed vertical lines in sequence diagrams:lifelines

What are the symbols for a guard condition?[...]…

What are use cases?Describes the way users interact with the system

What are DFD fragments?Fragments of use cases

What is a level 0 DFD diagram?The class that everything runs into

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