McGraw-Hill/Irwin ©2008 The McGraw-Hill Companies, All Rights Reserved CHAPTER 11 SYSTEMS DEVELOPMENT

McGraw-Hill/Irwin ©2008 The McGraw-Hill Companies, All Rights Reserved SECTION 11.1 DEVELOPING ENTERPRISE APPLICATIONS

11-3 DEVLOPING SOFTWARE Software that is built correctly can transform as the organization and its business transforms Software that effectively meets employee needs will help an organization become more productive and enhance decision making Software that does not meet employee needs may have a damaging effect on productivity and can even cause a business to fail

11-4 DEVELOPING SOFTWARE As organizations’ reliance on software grows, so do the business-related consequences of software successes and failures including: –Increase or decrease revenue –Repair or damage to brand reputation –Prevent or incur liabilities –Increase or decrease productivity

11-5 THE SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC) Systems development life cycle (SDLC) – the overall process for developing information systems from planning and analysis through implementation and maintenance

11-6 THE SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC) 1.Planning phase – involves establishing a high-level plan of the intended project and determining project goals 2.Analysis phase – involves analyzing end- user business requirements and refining project goals into defined functions and operations of the intended system Business requirement – detailed set of business requests that the system must meet in order to be successful

11-7 THE SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC) ) 3.Design phase – involves describing the desired features and operations of the system including screen layouts, business rules, process diagrams, pseudo code, and other documentation 4.Development phase – involves taking all of the detailed design documents from the design phase and transforming them into the actual system

11-8 THE SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC) 5.Testing phase – involves bringing all the project pieces together into a special testing environment to test for errors, bugs, and interoperability and verify that the system meets all of the business requirements defined in the analysis phase 6.Implementation phase – involves placing the system into production so users can begin to perform actual business operations with the system

11-9 THE SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC) 7.Maintenance phase – involves performing changes, corrections, additions, and upgrades to ensure the system continues to meet the business goals

11-10 SOFTWARE DEVELOPMENT METHODOLOGIES There are a number of different software development methodologies including: –Waterfall –Rapid application development (RAD) –Extreme programming –Agile

11-11 Waterfall Methodology Waterfall methodology – a sequential, activity-based process in which each phase in the SDLC is performed sequentially from planning through implementation and maintenance

11-12 Rapid Application Development Methodology (RAD) Rapid application development methodology (RAD) – emphasizes extensive user involvement in the rapid and evolutionary construction of working prototypes of a system to accelerate the systems development process The prototype is an essential part of the analysis phase when using a RAD methodology –Prototype – a smaller-scale representation or working model of the users’ requirements or a proposed design for an information system

11-13 Rapid Application Development Methodology (RAD)

11-14 Extreme Programming Methodology Extreme programming (XP) methodology – breaks a project into tiny phases, and developers cannot continue on to the next phase until the first phase is complete

11-15 Agile Methodology Agile methodology – a form of XP, aims for customer satisfaction through early and continuous delivery of useful software components –Agile is similar to XP but with less focus on team coding and more on limiting project scope –An agile project sets a minimum number of requirements and turns them into a deliverable product

11-16 DEVELOPING SUCCESSFUL SOFTWARE Primary principles for successful agile software development include: –Slash the budget –If it doesn’t work, kill it –Keep requirements to a minimum –Test and deliver frequently –Assign non-IT executives to software projects

McGraw-Hill/Irwin ©2008 The McGraw-Hill Companies, All Rights Reserved SECTION 11.2 THE SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC)

11-18 SDLC Large, complex IT systems take teams of architects, analysts, developers, testers, and users many years to create The systems development life cycle is the foundation for many systems development methodologies such as RAD and agile –Systems development life cycle – the overall process for developing information systems from planning and analysis through implementation and maintenance

11-19 SDLC

11-20 PHASE 1: PLANNING Planning phase – involves establishing a high-level plan of the intended project and determining project goals Primary planning activities include 1.Identify and select the system for development 2.Assess project feasibility 3.Develop the project plan

11-21 Identify and Select the System for Development Organizations use different forms of evaluation criteria to determine which systems to develop –Critical success factor (CSF) – a factor that is critical to an organization’s success

11-22 Identify and Select the System for Development

11-23 Assess Project Feasibility Feasibility study – determines if the proposed solution is feasible and achievable from a financial, technical, and organizational standpoint Different types of feasibility studies –Economic feasibility study –Operational feasibility study –Technical feasibility study –Schedule feasibility study –Legal and contractual feasibility study

11-24 Develop the Project Plan Developing the project plan is a difficult and important activity The project plan is the guiding force behind on-time delivery of a complete and successful system Continuous updating of the project plan must be performed during every subsequent phase during the SDLC

11-25 PHASE 2: ANALYSIS Analysis phase – involves analyzing end- user business requirements and refining project goals into defined functions and operations of the intended system Primary analysis activities include: 1.Gather business requirements 2.Create process diagrams 3.Perform a buy vs. build analysis

11-26 Gather Business Requirements Business requirements – the detailed set of business requests that the system must meet in order to be successful Different ways to gather business requirements –Joint application development (JAD) session – where employees meet to define or review the business requirements for the system –Interviews –Questionnaires –Observations –Review business documents

11-27 Gather Business Requirements The system users review the requirements definition document and determine if they will sign-off on the business requirements –Requirements definition document – contains the final set of business requirements, prioritized in order of business importance –Sign-off – the system users’ actual signatures indicating they approve all of the business requirements

11-28 Create Process Diagrams Process modeling – graphically representing the processes that capture, manipulate, store, and distribute information between a system and its environment Common process modeling diagrams include –Data flow diagram (DFD) – illustrates the movement of information between external entities and the processes and data stores within the system –Computer-aided software engineering (CASE) tools –automate systems analysis, design, and development

11-29 Create Process Diagrams Sample data flow diagram

11-30 Perform a Buy vs. Build Analysis An organization faces two primary choices when deciding to develop an information system 1.Buy the information system from a vendor –Commercial off-the shelf (COTS) – software package or solution that is purchased to support one or more business functions and information systems –SCM, CRM, and ERP solutions are typically COTS 2.Build the information system itself

11-31 Perform a Buy vs. Build Analysis Organizations must consider the following when making a buy vs. build decision: –Are there any currently available products that fit the needs? –Are there features that are not available and important enough to warrant the expense of in- house development? –Can the organization customize or modify an existing COTS to fit its needs? –Is there a justification to purchase or develop based on the acquisition cost?

11-32 Perform a Buy vs. Build Analysis Three key factors an organization should also consider when contemplating the buy vs. build decision 1.Time to market 2.Availability of corporate resources 3.Corporate core competencies

11-33 PHASE 3: DESIGN Design phase – involves describing the desired features and operations of the system including screen layouts, business rules, process diagrams, pseudo code, and other documentation Primary design activities include: 1.Design the IT infrastructure 2.Design system models

11-34 Design the IT Infrastructure Sample IT infrastructure

11-35 Design System Models Modeling – the activity of drawing a graphical representation of a design Different modeling types include: –Graphical user interface (GUI) –GUI screen design –Data model –Entity relationship diagram (ERD)

11-36 Design System Models Sample entity relationship diagram (ERD)

11-37 PHASE 4: DEVELOPMENT Development phase – involves taking all of the detailed design documents from the design phase and transforming them into the actual system Primary development activities include: 1.Develop the IT infrastructure 2.Develop the database and programs

11-38 PHASE 5: TESTING Testing phase – involves bringing all the project pieces together into a special testing environment to test for errors, bugs, and interoperability, in order to verify that the system meets all the business requirements defined in the analysis phase Primary testing activities include: 1.Write the test conditions 2.Perform the system testing

11-39 Write the Test Conditions Test condition – the detailed steps the system must perform along with the expected results of each step

11-40 Perform the System Testing Different types of testing –Unit testing – tests each unit of code upon completion –Application (or system) testing – verifies that all units of code work together –Integration testing – exposes faults in the integration of software components or units –Backup and recovery testing – tests the ability of an application to be restarted after failure –Documentation testing – verifies instruction guides are helpful and accurate –User acceptance testing (UAT) – tests if a system satisfies its acceptance criteria

11-41 PHASE 6: IMPLEMENTATION Implementation phase – involves placing the system into production so users can begin to perform actual business operations with the system Primary implementation activities include: 1.Write detailed user documentation 2.Determine implementation method 3.Provide training for the system users

11-42 Write Detailed User Documentation System users require user documentation that highlights how to use the system User documentation – highlights how to use the system

11-43 Determine Implementation Method Four primary implementation methods 1.Parallel implementation 2.Plunge implementation 3.Pilot implementation 4.Phased implementation

11-44 Provide Training for the System Users Organizations must provide training for system users Two most popular types of training include: –Online training – runs over the Internet or off a CD-ROM –Workshop training – set in a classroom- type environment and led by an instructor

11-45 PHASE 7: MAINTENANCE Maintenance phase – involves performing changes, corrections, additions, and upgrades to ensure the system continues to meet the business goals Primary maintenance activities include: 1.Build a help desk to support the system users 2.Perform system maintenance 3.Provide an environment to support system changes

11-46 Build a Help Desk to Support the System Users Internal system users have a phone number for the help desk they call whenever they have issues or questions about the system –Help desk – a group of people who respond to internal system user questions Providing a help desk is an excellent way to provide comprehensive support for new system users

11-47 Perform System Maintenance Maintenance – fixing or enhancing an information system Different types of maintenance include: –Adaptive maintenance –Corrective maintenance –Perfective maintenance –Preventative maintenance

11-48 Support System Changes An organization must modify its systems to support the business environment It typically accomplishes this through change management systems and change control boards –Change management system – a collection of procedures to document a change request and define the steps necessary to consider the change based on the expected impact of the change –Change control board (CCB) – responsible for approving or rejecting all change requests

11-49 SOFTWARE PROBLEMS ARE BUSINESS PROBLEMS Primary reasons for project failure include –Unclear or missing business requirements –Skipping SDLC phases –Failure to manage project scope Scope creep – occurs when the scope increases Feature creep – occurs when extra features are added –Failure to manage project plan –Changing technology

11-50 SOFTWARE PROBLEMS ARE BUSINESS PROBLEMS Find errors early: the later in the SDLC an error is found - the more expensive it is to fix