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BUSINESS PLUG-IN B14

Systems Development

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LEARNING OUTCOMES

1. Summarize the activities associated with the planning phase in the SDLC

2. Summarize the activities associated with the analysis phase in the SDLC

3. Summarize the activities associated with the design phase in the SDLC

4. Summarize the activities associated with the development phase in the SDLC

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LEARNING OUTCOMES

5. Summarize the activities associated with the testing phase in the SDLC

6. Summarize the activities associated with the implementation phase in the SDLC

7. Summarize the activities associated with the maintenance phase in the SDLC

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Introduction

• 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

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Introduction

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Systems Development Life Cycle - PHASE 1: PLANNING

• Planning phase – involves establishing a high-level plan of the intended project and determining project goals

• Primary planning activities include1. Identify and select the system for

development2. Assess project feasibility3. Develop the project plan

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PLANNING 1: 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

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PLANNING 1: Identify and Select the System for Development

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PLANNING 2: 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

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PLANNING 3: 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

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Systems Development Life Cycle – 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

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ANALYSIS 1: 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

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ANALYSIS 1: 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

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ANALYSIS 2: 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

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ANALYSIS 2: Create Process Diagrams

• Sample data flow diagram

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ANALYSIS 3: Perform a Buy vs. Build Analysis

• An organization faces two primary choices when deciding to develop an information system1. 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

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ANALYSIS 3: 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?

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ANALYSIS 3: 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

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Systems Development Life Cycle – 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

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DESIGN 1: Design the IT Infrastructure

• Sample IT infrastructure

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DESIGN 2: 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)

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DESIGN 2: Design System Models

• Sample entity relationship diagram (ERD)

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Systems Development Life Cycle – 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

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Systems Development Life Cycle – 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 conditions2. Perform the system testing

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TESTING 1: Write the Test Conditions

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

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TESTING 2: 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

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Systems Development Life Cycle – 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

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IMPLEMENTATION 1: Write Detailed User Documentation

• System users require user documentation that highlights how to use the system

• User documentation – highlights how to use the system

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IMPLEMENTATION 2: Determine Implementation Method

• Four primary implementation methods 1. Parallel implementation

2. Plunge implementation

3. Pilot implementation

4. Phased implementation

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IMPLEMENTATION 3: 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

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Systems Development Life Cycle – 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

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MAINTENANCE 1: 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

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MAINTENANCE 2: Perform System Maintenance

• Maintenance – fixing or enhancing an information system

• Different types of maintenance include:– Adaptive maintenance – Corrective maintenance – Perfective maintenance – Preventative maintenance

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MAINTENANCE 3: PROVIDE AN ENVIRONMENT TO 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

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CLOSING CASE ONEDisaster at Denver International Airport

• DIAs baggage system relied on 300 computers to route bags and 4,000 telecars to carry luggage across 21 miles of track

• Due to baggage system failures, DIA delayed its opening for 16 months, costing taxpayers roughly $1 million per day, which totaled around $500 million

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CLOSING CASE ONE QUESTIONS

1. 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

2. Evaluate the different implementation approaches. Which one would have most significantly increased the chances of the project’s success?

3. 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?

4. Why could BAE not take an existing IT infrastructure and simply increase its scale and expect it to work?

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CLOSING CASE TWOReducing Ambiguity in Business Requirements

• The number one reason projects fail is bad business requirements

• Business requirements are considered “bad” because of ambiguity or insufficient involvement of end users during analysis and design

• A requirement is unambiguous if it has the same interpretation for all parties

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CLOSING CASE TWO QUESTIONS

1. Why are ambiguous business requirements the leading cause of system development failures?

2. Why do the words “and” and “or” tend to lead to ambiguous requirements?

3. Research the web and determine other reasons for “bad” business requirements

4. What is wrong with the following business requirement: “The system must support employee birthdays since every employee always has a birthday every year”