SYSTEMS ANALYSIS DESIGN PHASE 2 SYSTEMS ANALYSIS Evaluating

SYSTEMS ANALYSIS & DESIGN PHASE 2 SYSTEMS ANALYSIS Evaluating Alternatives and Strategies

Chapter 5 Evaluating Alternatives and Strategies SYSTEMS ANALYSIS & DESIGN 3 E PHASE 2 2

Objectives PHASE 2 3 à Evaluate various alternatives when planning systems development and acquisition à Explain the advantages and disadvantages of in-house development versus purchasing a software package à List the steps in purchasing and evaluating a software package SYSTEMS ANALYSIS & DESIGN 3 E

Objectives PHASE 2 4 à Explain the differences between a request for proposal (RFP) and a request for quotation (RFQ) à Describe the contents of the system requirements document and explain its purpose à Explain the prototyping process and describe a typical situation where prototyping is used SYSTEMS ANALYSIS & DESIGN 3 E

Objectives PHASE 2 5 à Describe computer-aided software engineering (CASE) tools and explain how they are used during the systems development life cycle à Explain how systems flowcharts and statetransition diagrams are used SYSTEMS ANALYSIS & DESIGN 3 E

Introduction PHASE 2 6 à Chapter 5 covers the remaining tasks in the systems analysis phase à Evaluation of alternative solutions à Preparation of the system requirements document à Presentation to management SYSTEMS ANALYSIS & DESIGN 3 E

Evaluating Software Alternatives à Make or buy decision à In-house software à Developed by the company’s IS department à Software package à Purchased or leased from software publishers or vendors à Horizontal application à Vertical application SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -1 PHASE 2 7

Evaluating Software Alternatives PHASE 2 8 à Developing software in-house à Reasons for in-house development à Satisfy unique requirements à Minimize changes in business procedures and policies à Meet constraints of existing systems à Meet constraints of existing technology à Develop internal resources and capabilities SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -2

Evaluating Software Alternatives PHASE 2 9 à Buying a software package à Reasons for buying a software package à Lower costs à Requires less time to implement à Proven reliability and performance benchmarks à Implemented by other companies à Requires less technical development staff à Future upgrades provided by the vendor SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -2

Evaluating Software Alternatives PHASE 2 10 à Customizing software packages à Purchase a basic package that can be customized to suit your needs à Negotiate with software vendor to make enhancements to suit your needs à Purchase the package and make your own modifications SYSTEMS ANALYSIS & DESIGN 3 E

Evaluating Software Alternatives à Other software alternatives à Outsourcing à End-user systems à Enterprise computing SYSTEMS ANALYSIS & DESIGN 3 E PHASE 2 11

Evaluating Software Alternatives PHASE 2 12 à Outsourcing à Using outside companies to handle part of the workload, on short-term or long-term basis à Contract personnel firms à Systems management or facilities management firms SYSTEMS ANALYSIS & DESIGN 3 E

Evaluating Software Alternatives PHASE 2 13 à End-user systems à Major factor in systems planning and development à Applications can be managed by end-users SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -3

Evaluating Software Alternatives PHASE 2 14 à End-user systems à Major factor in systems planning and development à Applications can be managed by end-users à Software suites offer integrated applications à Interactive Help features include wizards à Security concerns might require read-only files à Information centers (IC) can support enduser systems SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -4

Evaluating Software Alternatives PHASE 2 15 à Enterprise computing à Overall information management strategy à Key is effective integration of information resources à Many systems involve client/server architecture SYSTEMS ANALYSIS & DESIGN 3 E

Evaluating Software Alternatives PHASE 2 16 à Selecting a software alternative à Decision will affect remaining SDLC phases à Systems analyst’s involvement depends on which alternative is selected SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -5

Steps in Evaluating and Purchasing Software Packages PHASE 2 17 à Five step process 1. Evaluate the information system requirements 2. Identify potential software vendors 3. Evaluate software package alternatives 4. Make the purchase 5. Install the software package SYSTEMS ANALYSIS & DESIGN 3 E

Steps in Evaluating and Purchasing Software Packages PHASE 2 18 Step 1: evaluate the information system requirements à Identify the key features of the system à Estimate volume and future growth à Specify any hardware constraints à Prepare a request for proposal or quotation SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -6

Steps in Evaluating and Purchasing Software Packages PHASE 2 19 Step 2: identify potential software vendors à Next step is to contact potential vendors à An RFP will help vendors to identify solutions à Various sources of information on suppliers à Retailers à Computer manufacturers à Industry trade journals à Systems consultants SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -7

Steps in Evaluating and Purchasing Software Packages PHASE 2 20 Step 3: evaluate software package alternatives à Object is to compare software packages and select the best alternative à Obtain information from many sources à Vendor presentations and literature SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -8

Steps in Evaluating and Purchasing Software Packages PHASE 2 21 Step 3: evaluate software package alternatives à Object is to compare software packages and select the best alternative à Obtain information from many sources à Vendor presentations and literature à Product documentation à Trade publications à Companies that perform software testing/evaluation SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -9

Steps in Evaluating and Purchasing Software Packages PHASE 2 22 Step 3: evaluate software package alternatives à Object is to compare software packages and select the best alternative à Obtain information from many sources à Vendor presentations and literature à Product documentation à Trade publications à Companies that perform software testing/evaluation à Contact users of the package Click to see Figure 5 -10 a à Benchmark test SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -10 b

Steps in Evaluating and Purchasing Software Packages Step 4: make the purchase à Software licenses à Lease agreements à Maintenance agreements SYSTEMS ANALYSIS & DESIGN 3 E PHASE 2 23

Steps in Evaluating and Purchasing Software Packages Step 5: install the software package à Installation time depends on size and complexity à Before using the package, complete all implementation steps à Loading, configuring, and testing the software à Training users à Converting data files to new format SYSTEMS ANALYSIS & DESIGN 3 E PHASE 2 24

PHASE 2 25 Hardware Alternatives à Hardware decisions use the same five-step approach as software decisions à Evaluate system requirements à Identify potential hardware vendors à Evaluate hardware alternatives à Make the purchase à Install the hardware SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -11

Hardware Alternatives PHASE 2 26 à Other issues to consider à Turnkey systems à Site preparation à New workstations à Network cabling à Raised floors à Conditioned electrical lines à Fire extinguishing equipment à Uninterruptible power supplies (UPSs) SYSTEMS ANALYSIS & DESIGN 3 E

TRADEOFF PHASE 2 27 à How do you select the best alternative? à Most companies combine à In-house developed software à Software packages à Outsourcing à End-user systems à Object is to develop a list of viable alternatives à All viable alternatives must be evaluated à Feedback from users is essential SYSTEMS ANALYSIS & DESIGN 3 E

A KEY QUESTION PHASE 2 28 à How will you prepare for the meeting with Doug Sawyer? à What is your strategy and how will you present your alternatives? à Consider the pros and cons of in-house development vs. purchase of a package SYSTEMS ANALYSIS & DESIGN 3 E

Completion of Systems Analysis PHASE 2 29 à System requirements document à Also called software requirements specification à Describes alternatives and makes recommendation to management à Similar to a contract for what will be delivered à Must be clear and understandable to users SYSTEMS ANALYSIS & DESIGN 3 E

Completion of Systems Analysis PHASE 2 30 à Presentation to management à Five probable management decisions 1. Develop an in-house system 2. Modify the current system 3. Purchase or customize a software package 4. Perform additional systems analysis work 5. Stop all further work SYSTEMS ANALYSIS & DESIGN 3 E

Completion of Systems Analysis PHASE 2 31 à Presentation guidelines and suggestions à Give overview of the project’s purpose and objectives à Summarize alternatives, with costs, pros, and cons à Explain why the recommended alternative was chosen à Allow time for discussion, questions, and answers à Obtain final decision from management or timetable for next step SYSTEMS ANALYSIS & DESIGN 3 E

Prototyping PHASE 2 32 à A prototype is an early, rapidly constructed working version of the system à A working model helps users understand the system à Prototyping produces a less-expensive model à Can eliminate problems before the final version SYSTEMS ANALYSIS & DESIGN 3 E

Prototyping PHASE 2 33 à Prototyping software tools à Nonprocedural tools specify the problem to be solved, rather than how to solve it à Fourth-generation environment prototyping tools à CASE toolkit SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -12

Prototyping PHASE 2 34 à Prototyping software tools à Nonprocedural tools specify the problem to be solved, rather than how to solve it à Fourth-generation environment prototyping tools à CASE toolkit à Report writer or report generator SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -13

Prototyping PHASE 2 35 à Fourth-generation environment prototyping tools à CASE toolkit à Report writer or report generator à Query language à Screen generator, screen painter, screen mapper, or form generator à Program generator or code generator à Fourth-generation language (4 GL) Click to see Figure 5 -14 a SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -14 b

PHASE 2 36 Prototyping à Prototyping during systems analysis à Goal is to develop a working model quickly à Early way to test essential system features à Prototype can be upgraded or replaced during later SDLC phases SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -15

Computer-Aided Software Engineering (CASE) PHASE 2 37 à CASE tools increase productivity à Full set of CASE tools is called a toolkit à CASE tools can handle variety of tasks à Create and integrate data flow diagrams à Logical and physical design à Generation of program code à CASE tool example is Visible Analyst Click to see Figure 5 -16 SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -17

Computer-Aided Software Engineering (CASE) PHASE 2 38 à Categories of CASE tools à Diagramming tools SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -18

Computer-Aided Software Engineering (CASE) PHASE 2 39 à Categories of CASE tools à Diagramming tools à Prototyping tools à Central repository Click to see Figure 5 -19 a SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -19 b

Computer-Aided Software Engineering (CASE) PHASE 2 40 à Categories of CASE tools à Diagramming tools à Prototyping tools à Central repository à Data design tools à Project management tools à Maintenance tools à Another CASE example: Hyper Analysis Toolkit (HAT) SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -20

Computer-Aided Software Engineering (CASE) PHASE 2 41 à Using CASE tools à Data design tool à Programming tool à Program debugger à Code generator à Project management tool à Maintenance tool Click to see Figure 5 -21 a SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -21 b

Computer-Aided Software Engineering (CASE) PHASE 2 42 à Categories of tools à Forward engineering tools (used during SDLC work) à Reverse engineering tools (convert program code into design specifications) à Reengineering toolkit (uses reverse and forward engineering) à Front-end, or upper-CASE tools (used in first three SDLC phases) à Back-end, or lower-CASE tools (used during systems implementation and operation phases) SYSTEMS ANALYSIS & DESIGN 3 E

TRADEOFF PHASE 2 43 à Pros and cons of CASE tools à Advantages à Automate manual tasks à Encourage standard methods à Improve accuracy and overall quality of end product SYSTEMS ANALYSIS & DESIGN 3 E

TRADEOFF PHASE 2 44 à Disadvantages à Cost of CASE software and hardware needed à Lack of CASE standards à Other issues à CASE does not replace need for analyst’s skills à Initial preparation effort not always worthwhile SYSTEMS ANALYSIS & DESIGN 3 E

A KEY QUESTION PHASE 2 45 à Does the new CASE toolkit at Sunnyside Beverages replace the need to teach new analysts how to create DFDs? à How would you respond? SYSTEMS ANALYSIS & DESIGN 3 E

Alternative Graphical Tools PHASE 2 46 à Other tools can be used in addition to DFDs à Systems flowcharts à State-transition diagrams SYSTEMS ANALYSIS & DESIGN 3 E

Alternative Graphical Tools PHASE 2 47 à Systems flowcharts à Display major process, input, and output operations à Primarily used in physical modeling à Various symbols represent data or files in specific physical media à Shape of symbol indicates the purpose à Lines with arrowheads indicate the flow of data SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -22

Alternative Graphical Tools PHASE 2 48 à State-transition diagrams à Show time sequence of real-time systems à A real-time system processes data and feeds it back to the system à Real-time system examples à Automobile cruise control systems à Microprocessor-controlled thermostats à Microwave oven control system Click to see Figure 5 -23 SYSTEMS ANALYSIS & DESIGN 3 E Click to see Figure 5 -24

Transition to Systems Design PHASE 2 49 à Next SDLC phase is system design for inhouse system development à Size of the development team depends on the company and the nature of the project à System requirements document à An accurate and understandable document is essential à Document contains design for the new system à Must reflect thorough analysis and effective communication SYSTEMS ANALYSIS & DESIGN 3 E

SOFTWEAR, LIMITED PHASE 2 50 à Rick and Carla attend training workshop for SWL’s new CASE toolkit: Visible Analyst à The development team evaluates various alternatives and potential solutions à The IS department recommendations: 1. Purchase a commercial package for payroll functions from Pacific Software Solutions 2. Develop an ESIP system in-house to meet SWL’s unique requirements SYSTEMS ANALYSIS & DESIGN 3 E

SOFTWEAR, LIMITED PHASE 2 51 à Other tasks accomplished by Rick and Carla à Completed the logical model, alternative evaluations, and cost/time estimates à Prepared the system requirements document à Printed and distributed the document à Scheduled a presentation to management à Prepared and rehearsed the presentation à Developed visual aids à Tried to anticipate questions SYSTEMS ANALYSIS & DESIGN 3 E

SOFTWEAR, LIMITED PHASE 2 52 à Results of the presentation à Recommendation was approved à Top managers indicated support for the project à The next step à Negotiate a contract with Pacific Software Solutions for purchase of the payroll package à Begin systems design work for the ESIP system SYSTEMS ANALYSIS & DESIGN 3 E