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CHAPTER 19

Building Software

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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

Define the relationship between the systems development life cycle and software development methodologies

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Overview

Software that is built correctly can support agile organizations and 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

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Overview

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

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Systems Development Life Cycle (SDLC)

SDLC - the overall process for developing information systems from planning and analysis through implementation and maintenance

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SDLC: Planning

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

When creating a feasibility study, it is important to focus on Economic feasibility- assesses the costs and benefits

of the new system – “Is building the new system cost effective?”

Operational feasibility evaluates whether people in the organization will use the new system – “Will the new system be used by the people in the organization?”

Technical feasibility examines the technical aspects of the new system – “Is it technically possible to create the new system?”

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SDLC: Analysis Phase

Analysis phase – involves analyzing end-user business requirements and refining project goals into defined functions and operations of the intended system

Business requirements – the detailed set of business requests that the system must meet in order to be successful

Three steps: understanding the old system identifying how the old system can be improved developing specifications for the new system

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SDLC: Design Phase

Design phase – involves describing the desired features and operations of the system including screen layouts, business rules, process diagrams, pseudo code, and other documentation

The design phase addresses "how" the system will accomplish the objectives

During the design phase, each portion of the new system is designed in detail, including the user interface, data structure, and the program design

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SDLC: Development & Testing Phases

Development phase – involves taking all of the detailed design documents from the design phase and transforming them into the actual system

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

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SDLC: Implementation Phase

Implementation phase – involves placing the system into production so users can begin to perform actual business operations with the system

Four types of conversion methods parallel conversion pilot conversion phased conversion plunge conversion

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SDLC: Maintenance phase

Maintenance phase – involves performing changes, corrections, additions, and upgrades to ensure the system continues to meet the business goals

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Software Development Methodologies

Waterfall Rapid application development (RAD) Extreme programming Agile

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Waterfall methodology

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

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Rapid application development methodology (RAD) 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

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Extreme programming (XP) methodology XP methodology – breaks a project into tiny phases,

and developers cannot continue on to the next phase until the first phase is complete

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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

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Principles for successfulagile software development

Slash the budget – Small budgets force developers and users to focus on the essentials

If it doesn’t work, kill it – Bring all key stakeholders together to evaluate and assess the software

Keep requirements to a minimum – Start each project with what the software must absolutely do

Test and deliver frequently – As often as once a week, complete a part of the project

Assign non-IT executives to software projects – Non-IT executives should coordinate with the technical project manager, test iterations to make sure they are meeting user needs, and act as liaisons between executives and IT

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Project Management

Project management – the application of knowledge, skills, tools, and techniques to project activities in order to meet or exceed stakeholder needs and expectations from a project

Project management software – supports the long-term and day-to-day management and execution of the steps in a project

Project managementinterdependent variables

Common reasonswhy IT projects fall behind schedule or fail

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Opening Case Study Questions

1. List and describe the seven phases in the systems development life cycle and determine which phase is most important to Cisco when it is developing software

2. Review the primary principles of successful software development and prioritize them in order of importance for Amazon.com’s business strategy

3. Explain why building agile software is important to all seven of the companies

4. Assess the impact to IBM’s business if it decided to use the waterfall methodology to build its customers’ information systems