Systems analysis and development CIS210 ch 07

CIS 210Systems Analysis and Development Week 4 Part I Structuring System Process Requirements... Objectives • Upon completion of part I you will be able to: – Understand and be able to e

CIS 210

Systems Analysis and Development

Week 4 Part I

Structuring System Process Requirements

Objectives

• Upon completion of part I you will be able to:

– Understand and be able to explain the concepts related to the logical modeling process

– Understand and be able to draw data flow diagrams

– Understand and be able to decompose data flow diagrams into lower-level diagrams

– Understand and be able to balance higher-level and lower-level data flow diagrams

– Understand and be able to explain the concepts related to the differences between the four types of DFDs

– Understand and be able to explain the concepts related to

Oracle’s process modeling tool and with functional hierarchy diagrams

• Data Flow Diagrams

– Model data flow

– Data flow relationships

– Change processes

– Also called process models

Process Modeling

• Overview

– Data flow diagram is common form

• Modeling a Systems Process for Structured Analysis

– Analysis team

– Organization of information

• Deliverables and outcomes

– Context diagram

– Diagrams of current system

– Logical data flow diagrams

– Data flow and functional requirements

– Entries of all objects in project dictionary

Diagramming Mechanics

Diagramming Mechanics

Diagramming Mechanics

• Decomposition of DFDs

– From one system to multiple systems – Functional decomposition

– Iterative process

– Finer and finer detail

– Primitive DFD

• Balancing DFDs

– Balancing inputs and outputs

Types of DFDs

• Current Physical

– People’s names

– Positions

• Current Logical

– Current system reduced to its essence – Data and processes

• New Logical

– Additional functions

– Obsolete functions removed

• New Physical

– Automated and manual functions

Using Data Flow Diagramming in Analysis

• DFD Guidelines

– Completeness

– Consistency

– Timing considerations

– The iterative nature of drawing DFDs

– Primitive DFDs

Using Data Flow Diagramming in Analysis

• Using DFDs as Analysis Tools

– Gap analysis

– Redundant data flows

– Unused data

– Inefficiencies

– Current logical vs new logical

• Using DFDs in Business Process Reengineering

Use Cases

• What is a Use Case

– Shows behaviors or functionality – Set of sequences

– Use case

– Actor

• Use Case Diagram

– Depicted diagrammatically

• Written Use Cases

• Modeling a systems process for structured analysis

• Data flow diagram symbols

• Rules governing data flow diagramming

• Decomposition of DFDs

• Balancing DFDs

• The four types of DFDs

• DFD guidelines

• Using DFDs as analysis tools

• Use cases