PART 2 Information Systems Development

LEARNING OBJECTIVES Systems Development Life Cycle Application Development Methodologies Project Management Systems Acquisition Development Phases in a Structured Process

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Information Systems Planning Process

SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC) Overview

Where Do Systems Development Projects Come From? Problem – an actual undesirable situation that prevents the organization from fully achieving its purpose, goals, and/or objectives. Opportunity – a chance to improve the organization even in the absence of an identified problem. Directive - a new requirement that is imposed by management, government, or some external influence/parties.

System Analysis & Design Approaches in a Nutshell DEVELOPMENT – Modeling – Prototyping (RAD) IMPLEMENTATION – Build (In-house) – Buy (COTS)

System Construction Process 1.Identify an IT problem to solve 2.Break the large problem into several smaller, more manageable units 3.Translate each unit (small problem) into computer programs 4.Piece together each program into an overall comprehensive IS that solves the problem

System Construction Process …

Strategies for Acquiring IT Applications Buy the applications (off-the-shelf approach) Lease the applications Software-as-a-Service (Cloud Computing) Use Open-Source Software Outsourcing Developing the applications in-house

SYSTEMS DEVELOPMENT PROCESS 1.System Identification, Selection, and Planning 2.System Analysis 3.System Design 4.System Implementation 5.System Maintenance

Systems Development Process Scope Definition Phase – What Business Problem Analysis Phase – What System Issues (Info / Data, Processes, Communications / Interfaces), – What User Needs, – What to Do - Conceptual Model – What Solution Design Phase – How to Do - Physical Model Implementation / MaintenancePhase – Do it, use it, keep it good

Systems Development Life Cycle …

Systems Development Life Cycle in Practice

Phase 1: System Identification, Selection, and Planning

– Undertake only those projects critical to mission, goals, and objectives – Select a development project from all possible projects that could be performed – Different evaluation criteria used to rank potential projects

Phase 1: System Identification, Selection, and Planning... Evaluation criteria Strategic alignment Potential benefits Potential costs and resource availability Project size / duration Technical difficulty / risks

Evaluation Criteria

Phase 2: Systems Analysis

Phase 2: System Analysis... Requirements collection Interviews Questionnaires Observations Document analysis Critical Success Factors (CSF) Joint Application Design (JAD)

Pros & Cons of CSF

Pros & Cons of JAD

Phase 2: System Analysis...  Modeling Organizational Data Entity Relationship Diagram (ERD)  Modeling Organizational Processes and Logic Data Flow Diagram (DFD) Processing Logic

A Process Model

A Data Model

Phase 3: System Design

Phase 3: System Design... Designing forms and reports Designing interfaces and dialogues Designing databases and files Designing processing and logic

Phase 4: System Implementation

Phase 4: System Implementation... Software programming Software testing Developmental (check program logic) Alpha testing (simulated data) Beta testing (real data)

System Testing

Phase 4: System Implementation... System conversion Parallel Direct / Cut-off Phased Pilot System documentation, training, and support User and reference guides Training and tutorials Installation procedures and troubleshooting guides

User Training

Phase 5: System Maintenance... Maintenance process steps: 1.Obtain maintenance request 2.Transform requests into changes 3.Design changes 4.Implement changes

Phase 5: System Maintenance...

Maintenance types: 1.Corrective maintenance 2.Adaptive maintenance 3.Perfective maintenance 4.Preventive maintenance

Software Maintenance

1.Limited IS staff 2.IS staff has limited skill set 3.IS staff is overworked 4.Problems with performance of IS staff 5.Reinvent the wheel (Common business functions) Need for Alternatives to In-house Development

Commercial Off-the-Shelf Software Advantages – Fast implementation of new system (many functions are similar across businesses, no need to build them from scratch.) – No need for expertise and staff for in-house development – Low development costs (but expensive to customize and implement !!!) – Vendors are responsible for software improvements and error corrections

Commercial Off-the-Shelf Software... Disadvantages – Dependent on the vendors – Future upgrade/customization is expensive – A COTS rarely reflects ideal solution developed in-house – Changing current business processes to fit the COTS

System Proposal & Project Management Feasibility Analysis Alternative (Candidate) System Solutions. Cost-benefit Analysis System Proposal Reports Project Management

Feasibility Analysis Feasibility is the measure of how beneficial or practical the development of an information system will be to an organization. Creeping Commitment : feasibility should be measured throughout the life cycle as project scope expands over times.

Feasibility Analysis … T echnical feasibility is a measure of the practicality of a specific technical solution and the availability of technical resources and expertise. O perational feasibility is a measure of how well the solution will work in the organization. It is also a measure of how people feel about the system/project. E conomic feasibility is a measure of the cost- effectiveness of a project or solution. S chedule feasibility is a measure of how reasonable the project timetable is.

Cost-Benefit Analysis Costs: Development costs are one time costs that will not recur after the project has been completed. Operating costs are costs that tend to recur throughout the lifetime of the system. Such costs can be classified as: – Fixed costs — occur at regular intervals but at relatively fixed rates. – Variable costs — occur in proportion to some usage factor. Benefits: Tangible benefits are those that can be easily quantified. Intangible benefits are those benefits believed to be difficult or impossible to quantify.

Costs for a Proposed Systems Solution

Economic Feasibility Payback Analysis – Payback analysis is to determine if and when an investment will pay for itself. – Payback period is the period of time that will lapse before accrued benefits overtake accrued and continuing costs. Net Present Value – a dollar today is worth more than a dollar one year from now – Discount rate – a percentage that the business earns on investing money in other projects or investments: opportunity cost

Economic Feasibility … Return-on-Investment (ROI) Analysis – a technique that compares the lifetime profitability of alternative solutions. – ROI for a solution or project is a percentage rate that measures the relationship between the amount the business gets back from an investment and the amount invested. – Lifetime ROI =(estimated lifetime benefits – estimated lifetime costs) / estimated lifetime costs – Annual ROI = lifetime ROI / lifetime of the system

Feasibility Matrix

Scheduling Strategies Forward Scheduling – a project scheduling approach that establishes a project start date and then schedules forward from that date. Reverse Scheduling – a project scheduling strategy that establishes a project deadline and then schedules backward from that date.

Gantt Chart Incomplete Task Complete Task Legend ID Preliminary investigation Problem analysis Requirements analysis Decision analysis Design Construction Implementation MayJunJulAugSepOctNovDec 2001 Task Name Today

Measures of Project Success – The resulting information system is acceptable to the customer. – The system was delivered “on time.” – The system was delivered “within budget.” – The system development process had a minimal impact on ongoing business operations.

System Proposal

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