Systems analysis and development CIS210 ch 08

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

CIS 210

Systems Analysis and Development

Week 4 Part II

Structuring System Logic Requirements

Objectives

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

– Understand and be able to explain the concepts

related to using Structured English as a tool for

representing steps in logical processes in data flow diagrams

– Understand and be able to explain the concepts

related to decision tables and decision trees

– Understand and be able to explain the concepts

related to logical modeling

• Modeling Process Decision Logic

– Structured English

– Decision Tables

– Decision Trees

– Criteria for choosing logic modeling techniques

Logic Modeling

• Overview

– Internal structure

– Functionality of processes

– Analysis phase

• Modeling a System’s Logic

– Requirements structuring

• Deliverables and Outcomes

– Structured descriptions

– Diagrams outlining logic

– New entries

Structured English

• Conditional Statements

BEGIN IF

IF Quantity-in-stock is less than Minimum-order-quantity THEN GENERATE new order

ELSE DO nothing

END IF

• Repetition Statement

DO

READ Inventory records BEGIN IF

IF Quantity-in-stock is less than Minimum-order-quantity THEN GENERATE new order

ELSE DO nothing

END IF

UNTIL End-of-file

Decision Tables

• Overview

– Better for complicated logic

– Tabular form

• Components

– Condition stubs

– Action stubs

– Rules

– Procedures to follow

Decision Trees

• Overview

– Depicts a decision or choice situations – Nodes and branches

• Components

– Decision points

– Actions

– Rules

Making a Decision

• Modeling process decision logic

• Deliverables and outcomes of logic modeling

• Structured English

• Decision tables

• Decision trees

• Choosing amount decision logic methods