Rozy

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System Development and Documentation Techniques

Introduction

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This chapter will explains the most common systems of documentation tools and techniques that include data flow diagrams, document flowcharts, computer system flowcharts and program flowcharts. The purpose of this study is to achieve and satisfy the readers that what has been studied and defines in this chapter.

This chapter explains what Data flow diagrams are. Based on the study it is graphically describes the flow of data within an organization. A data flow diagram is also used for document existing systems and to plan and design new ones.

A data flow diagram is composed of four basic elements which are data source and destinations, data flows, transformation processes and data stores.

The charts below will explain on how DFD’s flows in an organization or in an existing systems.

It shows here that the input to process C is data flow B. which comes from data source A. The outputs of process C are data flows D and E. Data flow E is sent to data destination J .

Process F uses data flows D and G as input and produces data flow J and G as output. Data flow G comes from and returns to data store H. Data flow I is sent to destination K.

A data flow can consist of one or more pieces of datum. For example, data flow B (customer payment) consists of two parts: a payment and remittance data. Process payment will split into two data elements

And sends them in different directions. The remittance data flows to another process, where it is used to update accounts receivable records and the payment E is sent to a bank with a deposit slip.

It shows here that the process payment C takes the customer payment and splits it into the remittance data and the deposit. The update receivables F process takes the remittance data D and the accounts receivables H data and

produces an updated...