Unit 15: SDLC I October 12, 2015

Systems Development

Systems Development Life Cycle

SDLC is used for Developing New Software Systems, …both commercial and in-house and for Purchasing “Canned” Software, and for Customizing “Canned” Software

SDLC originated with Legacy Systems Produced custom-built software “Computerized” existing processes Early systems simply used the “computer” in lieu of paper and manual arithmetic

Overlooked the opportunity to improve those processes

How do you build new software? What are the steps to a new system?

Fordham’s Taxonomy Five Major Phases Plus Documentation throughout Plus Evaluation…

Fordham’s Taxonomy Preparation Phase Design Phase Development Phase Implementation Phase Maintenance Phase …. plus Evaluation …. Documentation throughout!

Identify the need for a new computer system Preparation Phase Feasibility Study Initial Scope Initial Timetable Initial Budget Estimate Formal Proposal to Management Management Approval and Funding

START FINISH

Identify the need for a new computer system Preparation Phase Feasibility Study Determination of Initial Scope Determination of Initial Budget Estimate Determination of Initial Timetable Submit Formal Proposal to Management Management Approval and Funding

Identify the need for a new computer system Feasibility Study Determination of Initial Scope Determination of Initial Budget Estimate Determination of Initial Timetable Submit Formal Proposal to Management Management Approval and Funding Preparation Phase

Scope, Time, Resources (budget) You can only specify TWO of the three. Specifying any TWO of the three automatically determines the third!

… Run Away!

Identify the need for a new computer system Feasibility Study Determination of Initial Scope Determination of Initial Budget Estimate Determination of Initial Timetable Submit Formal Proposal to Management Management Approval and Funding Preparation Phase

Assemble the Project Team

Traditional Balanced Team… USER SPECIALISTS End users Management Outside users Peripheral users Maintenance users TECHNICAL SPECIALISTS Programmers Network Designers Database Designers System Architects Comm. Specialists Dual-Specialty Team

Preparation Phase Design Phase Organize the team, and Establish Project Standards Assemble the Project Team

USER SPECIALISTS End users Management Outside users Peripheral users Maintenance users TECHNICAL SPECIALISTS Programmers Network Designers Database Designers System Architects Comm. Specialists Dual-Specialty Team

Order Entry System Purchasing Module Receiving Dock Module Accounts Payable Module Warehouse System Order Filling System Shipping Dock Module Billing System

START FINISH

PROJECT MANAGEMENT Gantt Chart PERT Chart Critical Path Method (CPM) etc.

Hardware Platform? Nomenclature Conventions? Standardized Screen Layouts? Standardized Report Layouts? Programming Language? Compiled or Interpreted? Wording Conventions? Program Structure? Documentation Requirements?

Preparation Phase Identification of User Needs Determination of Data Elements Input/Output Specifications -- Prototyping Determination of Data Flows Development of the Database Structure Design Phase Organize the team, and Establish Project Standards Assemble the Project Team

Questions?