CHAPTER 11 SYSTEMS DEVELOPMENT

CHAPTER ELEVEN OVERVIEW SECTION 11.1 – DEVELOPING ENTERPRISE APPLICATIONS Developing Software The Systems Development Life Cycle Software Development Methodologies Developing Successful Software SECTION 11.2 – THE SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC) Systems Development Life Cycle Phase 1: Planning Phase 2: Analysis Phase 3: Design Phase 4: Development Phase 5: Testing Phase 6: Implementation Phase 7: Maintenance Software Problems are Business Problems

DEVELOPING ENTERPRISE APPLICATIONS SECTION 11.1 DEVELOPING ENTERPRISE APPLICATIONS

LEARNING OUTCOMES Identify the business benefits associated with successful software development Describe the seven phases of the systems development life cycle

Summarize the different software development methodologies LEARNING OUTCOMES Summarize the different software development methodologies Define the relationship between the systems development life cycle and software development Compare the waterfall methodology and the agile methodology

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

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

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

THE SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC) Planning phase – involves establishing a high-level plan of the intended project and determining project goals 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

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

THE SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC) 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 Implementation phase – involves placing the system into production so users can begin to perform actual business operations with the system

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

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

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

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

Rapid Application Development Methodology (RAD)

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

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

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

OPENING CASE QUESTIONS HP’s Software Problems Identify the business benefits associated with successful software development for HP Which of the seven phases of the systems development life cycle is most important to HP? Which of the seven phases of the systems development life cycle is least important to HP? Which of the different software development methodologies should HP use to implement successful systems? Explain what might happen if HP used the waterfall methodology to develop its ERP system

THE SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC) SECTION 11.2 THE SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC)

LEARNING OUTCOMES Summarize the activities associated with the planning phase in the SDLC Summarize the activities associated with the analysis phase in the SDLC Summarize the activities associated with the design phase in the SDLC Summarize the activities associated with the development phase in the SDLC

LEARNING OUTCOMES Summarize the activities associated with the testing phase in the SDLC Summarize the activities associated with the implementation phase in the SDLC Summarize the activities associated with the maintenance phase in the SDLC

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

SDLC

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

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

Identify and Select the System for Development

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

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

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: Gather business requirements Create process diagrams Perform a buy vs. build analysis

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

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

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

Create Process Diagrams Sample data flow diagram

Perform a Buy vs. Build Analysis An organization faces two primary choices when deciding to develop an information system 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 Build the information system itself

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?

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

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: Design the IT infrastructure Design system models

Design the IT Infrastructure Sample IT infrastructure

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)

Design System Models Sample entity relationship diagram (ERD)

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: Develop the IT infrastructure Develop the database and programs

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: Write the test conditions Perform the system testing

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

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

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: Write detailed user documentation Determine implementation method Provide training for the system users

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

Determine Implementation Method Four primary implementation methods Parallel implementation Plunge implementation Pilot implementation Phased implementation

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

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: Build a help desk to support the system users Perform system maintenance Provide an environment to support system changes

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

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

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

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

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

OPENING CASE QUESTIONS HP’s Software Problems Describe the different types of feasibility studies and explain how HP could use a technical feasibility study to avoid software development failure Review the buy versus build decision and explain why HP chose to buy its ERP system Why is testing critical to HP’s software development process? Identify the primary reasons for software project failure and explain which ones HP experienced on its ERP build

CLOSING CASE ONE Denver International Airport One of the problems with DIA’s baggage system was inadequate testing. Describe the different types of tests DIA could have used to help ensure its baggage system’s success Evaluate the different implementation approaches. Which one would have most significantly increased the chances of the project’s success? Explain the cost of finding errors. How could more time spent in the analysis and design phase have saved Colorado taxpayers hundreds of millions of dollars? Why could BAE not take an existing IT infrastructure and simply increase its scale and expect it to work?

CLOSING CASE TWO Reducing Ambiguity Why are ambiguous business requirements the leading cause of system development failures? Why do the words “and” and “or” tend to lead to ambiguous requirements? Research the Web and determine other reasons for “bad” business requirements What is wrong with the following business requirement: “The system must support employee birthdays since every employee always has a birthday every year”

CLOSING CASE THREE Gearing Up at REI What business benefits did REI receive by developing its successful CRM system? Identify the potential issues facing REI if it failed to implement a successful SCM system List and describe the seven phases of the SDLC and rank them in order of importance to REI’s system development efforts

CLOSING CASE THREE Gearing Up at REI Summarize the different software development methodologies and recommend one for REI to follow Describe the analysis phase of systems development along with its importance for successful system development efforts for REI Explain the importance of the testing phase along with three different tests REI should perform on each new system