Systems analysis and development CIS210 ch 08

CIS 210 Systems Analysis and Development Week 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 Overview • 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 Summary • • • • • • Modeling process decision logic Deliverables and outcomes of logic modeling Structured English Decision tables Decision trees Choosing amount decision logic methods ... 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... decision or choice situations – Nodes and branches • Components – Decision points – Actions – Rules Making a Decision Summary • • • • • • Modeling process decision logic Deliverables and outcomes... 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