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IFS310: Module 4

Structured Methodology and COBOL

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IFS310: Module 4

OUTLINE OF CLASS

• Discussion– Structured Analysis and Design– Structured Programming (COBOL)– Systems Analysis Strategies

• Group Project

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IFS310: Module 4

Strategies for Systems Analysis and Problem Solving

• Modern Structured Analysis– Model

– Model-driven development

– Process Models - Data Flow Diagrams (DFDs)

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IFS310: Module 4

Structured Systems Analysis and Design Methodology (SSADM)

• A systems approach to the analysis and design of information systems.

• Involves the application of a sequence of analysis, documentation and design tasks.

• Uses a combination of text and diagrams throughout the whole life cycle of a system design, from the initial design idea to the actual physical design of the application.

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IFS310: Module 4

SSADM (cont.)

• SSADM uses a combination of three techniques: – Logical Data Modeling – Data Flow Modeling – Entity Behavior Modeling

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IFS310: Module 4

Structured programming

• A subset or subdiscipline of procedural programming, one of the major programming paradigms. It is most famous for removing or reducing reliance on the GOTO statement (also known as "go to").

• Break larger pieces of code into shorter subroutines (functions, procedures. methods, blocks, or otherwise) that are small enough to be understood easily.

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IFS310: Module 4

COBOL

• COBOL is a third-generation programming language. Its name is an acronym, for COmmon Business Oriented Language, defining its primary domain in business, finance, and administrative systems for companies and governments.

• COBOL did not support local variables, recursion, dynamic memory allocation, or structured programming constructs. Support for some or all of these features has been added in later editions of the COBOL standard.

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IFS310: Module 4

Structure of COBOL (Example)

• Handout

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Structure Chart

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IFS310: Module 4

What is System Analysis?

Systems analysis is the dissection of a system into its component pieces for purposes of studying how those component pieces interact and work.

Systems analysis is (1) the surveysurvey and planning of the system and project, (2) the studystudy and analysis of the existing business and information system, and (3) the definitiondefinition of business requirements and priorities for a new or improved system. A popular synonym is logical design.

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IFS310: Module 4

The Survey Phase

• Survey Problems, Opportunities, and Directives

• Negotiate Project Scope

• Plan The Project

• Present The Project

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IFS310: Module 4

Outputs of Survey Phase

• Project Charter

• Problem Statement

• Scope Statement

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IFS310: Module 4

The Study Phase

• Model the Current System – The overriding modeling strategy is

information hiding.– Data, Process, and Geographic Modeling

• Analyze Problems and Opportunities– cause/effect analysis.

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IFS310: Module 4

Page 1 of 5

PROBLEMS, OPPORTUNITIES, OBJECTIVES AND CONSTRAINTS MATRIX

Project: Member Services Information System Project Manager: Sandra Shepherd

Created by: Robert Martinez Last Updated by: Robert Martinez

Date Created: January 21, 1997 Date Last Updated: January 31, 1997

CAUSE AND EFFECT ANALYSIS SYSTEM IMPROVEMENT OBJECTIVES

Problem or Opportunity Causes and Effects System Objective System Constraint

1. Order response time is unaccept-able.

1. Throughput has increased whilenumber of order clerks was down-sized. Time to process a single or-der has remained relatively con-stant.

2. System is too keyboard dependent.Many of the same values are keyedfor most orders. Net result is (withthe current system) each ordertakes longer to process than isideal.

3. Data editing is performed by theAS/400. As that computer has ap-proached its capacity, order edit re-sponses have slowed. Because or-der clerks are trying to work fasterto keep up with the volume, thenumber of errors have increased.

4. Warehouse picking tickets for or-ders were never designed to maxi-mize the efficiency of order fillers.As warehouse operations grew, or-der filling delays were inevitable.

1. Decrease the time required to proc-ess a single order by 30%.

2. Eliminate keyboard data entry foras much as 50% of all orders.

3. For remaining orders, reduce asmany keystrokes as possible by re-placing keystrokes with point-and-click objects on the computer dis-play screen.

4. Move data editing from a sharedcomputer to the desktop.

5. Replace existing picking ticketswith a paperless communicationsystem between member servicesand the warehouse.

1. There will be no increase in theorder processing workforce.

2. Any system developed must becompatible with the existing Win-dows 95 desktop standard.

3. New system must be compatiblewith the already approved auto-matic identification system (for barcoding).

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The Study Phase (cont.)

• Establish System Improvement Objectives and Constraints

• Modify Project Scope and Plan

• Present Findings and Recommendations

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IFS310: Module 4Analysis of the Current ___________ System

I. Executive summary (approximately 2 pages)A. Summary of recommendationB. Summary of problems, opportunities, and directivesC. Brief statement of system improvement objectivesD. Brief explanation of report contents

II. Background information (approximately 2 pages)A. List of interviews and facilitated group meetings conductedB. List of other sources of information that were exploitedC. Description of analytical techniques used

III. Overview of the current system (approximately 5 pages)A. Strategic implications (if the project is part of, or impacts an existing information

systems strategic plan)B. Models of the current system

1. Interface model (showing project scope)2. Data model (showing project scope)3. Geographic models (showing project scope)4. Process model (showing functional decomposition only)

IV. Analysis of the Current System (approximately 5-10 pages)A. Performance problems, opportunities, and cause/effect analysisB. Information problems, opportunities, and cause/effect analysisC. Economic problems, opportunities, and cause/effect analysisD. Control problems, opportunities, and cause/effect analysisE. Efficiency problems, opportunities, and cause/effect analysisF. Service problems, opportunities, and cause/effect analysis

V. Detailed recommendations (approximately 5-10 pages)A. System improvement objectives and prioritiesB. ConstraintsC. Project Plan

1. Scope reassessment and refinement2. Revised master plan3. Detailed plan for the definition phase

VI. AppendicesA. Any detailed system modelsB. (other documents as appropriate)

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The Definition Phase

• Outline Business Requirements

• Model Business System Requirements• Logical models depict what a system is, or what a

system must do – not ‘how’ the system will be implemented. Because logical models depict the essence of the system, they are sometimes called essential models

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Model Business System Requirements

Data Modeling Process Modeling Geographic Modeling (Network Modeling) Object Modeling

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The Definition Phase (cont.)

• Build Discovery Prototypes (opt.)

• Prioritize Business Requirements– Timeboxing is a technique which develops larger fully

functional systems in versions.

• Modify the Project Plan and Scope

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Deliverables

• Business Requirements Statement – “Big Picture” of the system– Trigger of the systems design

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Group Project

• Objectives– Milestone 1 (if not done yet)– Milestone 2

• Overviews

• Problem Statement

• Narrative descriptions of processes (data flows, data stores, external entities)