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SDLC
- Syestem development life scyle
- Planning
- Analysis
- Design
- Implementation
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Planning
- Understanding why a system should be build and how it benefits the business
- Project initiation
- Create System request
- Conducte Feasibility analysis
- and both are presented to approval committee
- Once approved moves to prokect managment
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System Request
- Summary of a buiness need and it explains how a system that supports the need will create business value
- Created by project sponser
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Project Managments
- Project manager makes a work plan
- The deliveralbe for them is the project plan which describes how the team will go about developing the system
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Analysis
- Who will use the system
- What the system will use
- Where and When it will be used
- First step of design of new system not just analysis
- 3 Steps
- 1) Analysis strategy: Analysis of the current system (as-is) and ways to desine a new to-be system
- 2)Requirments gathering through interviews or questionairs which leads to devlep of a concpt for new system and then creates analysis models
- 3) Systm proposal which is created from a combo of analyses, system concep, and models and presented to porject sponsor
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Design
- How the system will operate in terms of hardware, sofware and netweork infrastructure
- 4 steps:
- 1) Design stragegy first developed by own porgrmamers, oursourced, or buy
- 2) Architecture design describes hardware, sofware and network infra to be used where interface design says how users move throughs system
- 3) Database and file specifications are developed
- 4) program desgn is creaed by analysts team which says what each program does
- System specification is combination of these documnets that is handed to programing team
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Implementation
- System acutlally built
- Gets most attention
- 3 Steps:
- 1) Construction to system where it is built and tested
- 2) Installation old system is turned off and the new one is turned on. Parallel, direct or phased approach. Must provide training plan to users
- 3) Support Plan which included formal or informa post implementation review as well as way to identify major or minor change
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Gradual Refinement in SCLC
As you progress through each stage, the prvious phase refines and elaborates on the work done previously
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Process-centered Methodologies
- Emphasize process models
- Focus first on defining processs
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Data-centered Methodologies
- Emphasize data modesl as teh core of teh system concep
- First focus on defining the contents of the storage area and how contents organized
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Object-oriented methodologies
Balance between process and data
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Structured Design
- Follow systematic step by step approach and moves logically from one phase to next
- Spend a lot of time within each phase
- Waterfall and Parallel deelopment
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Waterfall
- Proceed in sequence from one to the next
- Pros: Identifies system requirements way in advance and minmizes changes
- Cons: Design completely specified before programming begins and long time elapses between completion of sytem propoal and delivery of system
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Parallell
- Does a genral design for te whole system and then divides the pojec tinto a series of distince subprojects tha can be designed and implemented in parallel
- Then all subprojects are combined and system delivered
- Pros: Reduce shcedule time to deliver a system so less chance of rework
- Cons: Still has problem of paper document and sometimes subprojects are not completely independent so may take significant integration efforts
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RAD
- Rapid Application Developmnet
- Attempt to release part of system right away to use it and suggest revisions
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Phased
- Breaks overall system into a series of
- Most important in first version and go through all steps each time just creating new versions
- Pros: Quickely get into users hands
- Cons: work with intentially incomplete so must have most important in first version
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Prototyping
- Performs all phases concurently
- First provide a quick and dirty first program with minimal things
- Make so they can work on it as they go and make changes as they need to
- Pros: Really quickly gets into users hands and reasures that they are working on it.
- Cons: fast pase and fundamental issure and problem are nto recognized until well into development process
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Throwaway-prototyping
- Have thourough analysis phase to gather ideas for system concept.
- A design prototype is made for those things not understood and is not a working system and is not transformed into overall sytem. Just meant to test ideas to understand
- used to minimize risk but can take longer
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Agile Developmnet
- Meant to eliminate much of the modelign and documentation
- Extemg porgramming, scrum and DSDM
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Extreame Programming
- Four cour values are communiatrion, simplicty, feedback, courage
- Everything is saved and there is contiuous testint simple coed and close interatctions with end users to build sytems quickly
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Key factors to Selcting a Methodology
- Clarity of user requirments
- Familiarity with technology
- Sysstem complexity
- System reliabliity
- Short time schedules
- Schedule visibilty
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Approval Committe
- Reviews system request
- Makes initial determination
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Steps for Assessing Project Feasibility
- 1) Identify Costs and Benefits
- 2) Assigne values to C&B
- 3) Determine Cash flow
- 4) Determine net present value
- 5) Determine ROI
- 6) Determine Breakeven point
- 7) Graph Breakeven point
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What makes project Risky?
- Lack of familuarity with functinal area
- Lack of familiarity with technology
- Larger projects
- Harder to inetgreate the sysem with the cmopany's existing technology
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ROI
How much money the org will recieve in return for the investment it will make
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Break-Even-Point
First year in which the system has greater brenetits than costs
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Present Value (PV)
- Amount of invenstment today capred to that same amount in the future
- Amount/(1+interest rate)^n
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Net Present Value (NPV)
- Present value of benefits less teh present value of cost
- PV Ben -PV Costs
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Return on Investment (ROI)
- Amount of revenues or scost savings results froma given investmetn
- Total ben - total cost/total cost
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Break-Even Point
- Point in time at which the cost of the porject equl the valie it has deliverd
- Yearly NPV- Cum NPV/Yearly NPV
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System Request
Document that describes the business reason for building a sytem and the value that the system is expected to provide
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5 Elements of System Request
- Project Sponsor
- Business Need
- Business requirments
- Business value
- Special Issues
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Project Sponsor
- Initiates project
- Serves as primary point of contact
- Completeds System Request
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Business Need
- Business related reason for initiating the system
- What the users will need it for
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Business Requirements
- Business capabilites that the system will need to provide
- More technical needs of system
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Business Value
Benefits created for organization
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Special issues
- Relevent to teh implemnentation of the system
- Time line
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Feasibility Analysis
- Create a more detailed business case to better understand the opportunities and limitation
- Guides org in determining whether to proceed or not
- Identifies important risk that is associated with project
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3 Techniques
- Technical
- Economic
- Organizational
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Technical Feasibility
- The extent to which the system can be successfully desgined, develooped and installed
- Can we build it?
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Economic Feasibility
- Cost benefit analysis
- Identifies financial risk
- Should we build it
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4 Categories of Costs and benefits
- Development costs
- Operational costs
- Tangible benefits
- Intangible benefits
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Development costs
- Tangible expenses from construction
- One time expenses
- Dev team salories
- Consultant fees
- Dev training
- Vendor Installation
- Office space and equip
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Operations Costs
- Tangible costs required to operate system
- Ongoing costs
- Salaties op staff
- Software license
- Hardwae repairs and upgrades
- Communications charges
- User Training
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Tangible benefits
- Revenues and cost savings
- Increased sales
- Reduction in staff
- Reduction in Inventory
- Reduction in IT Costs
- Better Supplier Prices
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Intangible Benefits
- Based on intuition and belief
- Increased Market share
- Higher Quality Products
- Improved Customer Service
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Organizational Feasibility
- How well acceped by users
- If we build it, witll they come?
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Strategic Alignment
- Fit between project and business strategy
- Greater the alignemnt the less risky
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Stakeholder Analysis
- Project champion, system users, and org mang.
- Soeone who can or will be affected by new system
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Champion
- Created the sysem request
- Promotes project
- Allocates time
- Provides resources
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Org. Man.
- Convey it will make a valuable contributin
- Encuarage to accept and use
- Budget money
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System Users
- Ultimately use once develped
- Hands on activities
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Outputs of each phase of SDLC
- Planning --> System request
- Analysis --> System proposal
- Design --> first models from analysis
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System Proposal
- Requirment def, functional and structural, behavioral models, feaibility analysis
- Also includes an executive summary, the system request, the work plan, the feasibility analysis, the requirements definition, and the evolving models that describe the new system.
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System Walkthrough
- Meeting at which the concept for the new system is presend to the useres, managers, and key decision makers
- Goal: explain system in moderate detail so those peple can clarly understand it, identify improvments, and make decision if it should continue
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Requirments
A staement of what the system must do or what characteristics it must have
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Business Requirment
- During analysis these are written
- What of the system
- Focus on the needs of business user
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System Requests
- Later in design business evolve
- From developers perspective
- Describe how will be implemented
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Requirments Definition
- Turn the very high level explantion of the business reqiremtns stated in the request ino a more precisce list of requiments
- Expansions of these lead to design phase
- Lists the nonfuncional and functional requirements in outline format
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Functinal Requirment
- Related directly to a process a system has to perform or information it needs to contain
- Define fuctions system must have without specifics
- Ex. ability to serch for available inventory
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Non-functional Requirments
- Refer to behavior properties that the system must have such as perfomrance and usability
- ex. access system using web browser
- Describes:
- -operational: physical and technical environment in which the system will operate
- -performance: Speed, capacity and reliability of the system
- -security: Who has authorized access to the system under what circumstances
- -cultual and political: these factors and legal requirements that affect the system
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Requirments gathering Techniques
- Interviews
- Questionnaires
- Observation
- JAD
- Document Analysis
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Interviews
- Most common way
- 5 Basic Steps
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5 steps for Intervies
- 1) Selecting interviewees: make a schedule for those who are to be interviewed, when, and for what purpose
- 2) Designing Interview Questions: There are three types of questions: closed-ended, open-ended, probing. Do not ask questions about information that is readily available from other sources
- 3) Preparing for the interview: Have a list of questions to be asked in the appropriate order. Also make sure to inform the interviewee of the reason for the interview and the areas that will be discussed.
- 4) Conducting Interview: First goal is to build rapport with interview then tell them reason and why they were chosen
- 5) Post Interview Follow-up: Prepare an interview report that describes the info from interview which should contain interview notes and should be written within 48 hours of interview
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Close-ended Questions
- They require a specific answer
- Use when looking for specific precise information
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Open-ended Questions
- Leave room for elaboration on the part of the interviewee
- Use when you want to gather rich info and you want to give the interviewwee more control over the info realeased
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Probing Questions
Follow up on what has just been discussed in order to learn more and are often used when interviewr is unclear about answer
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Structured Interviews
- Sets of questions deveoloped prior to interviw
- Usually close-ended
- Use to find out facts
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Unstructured interviews
- Have open ended questionst aht allows interviewr to probe for more information
- When things are unclear
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Top-down, Bottom up Interview
- Topdown: Starts with broad question and works towards specific. Start open ended to close ended questions
- Bottomup: Starts specific and goes broadd. Start close ended and go to open ended
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JAD
- Facilitator: Does not enter opinion. Expert in both group process techniques and system analysis and design techniques
- Select those based on information needed
- sticks to the agenda
- helps the group understand the technical terms and jargon that surrounds the system development
- records the group’s input on a public display area
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5 Major steps in conduction a JAD
- 1) Selecting Participants: Most competenet
- 2) Designing a JAD session: half day to several weeks, depending on the scope of the project. Most last five to ten days, spread over a three-week period.
- 3) Preparing for a JAD session: Participants must know what is expected of them, know the goal of a JAD session.
- 4) Conducting a JAD session: formal agenda, formal ground rules that define appropriate behavior.
- 5) Post-JAD follow up - a postsession report is prepared and circulated among session attendees.
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e-JAD
- An online JAD session
- Can reduce time required by 50-80 percent
- Can contribute at the same time
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Questionaire
- set of writtena questions used to obtain infor form individual s
- Good for outside the organization questions
- 30-50 percent paper and email returned
- Web-based is 5 -30 percent
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Designing Questionaire
- Improve response by telling purpose, incentives and follow up
- Important first
- Ananymous
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Document Analysis
- Uses As-is sytem documentation to review and examine system
- Gives strong indication of differences from formal and informal systems and what changes need to be made
- It is what they planned to do but not nessicsarily what they are doing
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Formal System
Written documents taht were from the development of the system such as user manual, paper reoprs
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Informal System
What the system is actually doing regardles of what the documentation says
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Observation
Helps gather info about as-is system becasue is shows the reality of the situation as well sass check validity
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Factors to Gather Info
- Type of info
- Depth of info
- Bredth of info
- Integration of info
- User invovlemnt
- Cost
- Compining tehcniques
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