process models report

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It is a hierarchical flowchart that allows the description of the

organization of data and procedures.

They were initially developed in France by Jean-Dominique

Warnier and in the US by Kenneth Orr.

This method aids the design of program structures byidentifying the output and processing results and then

working backwards to determine the steps and

combinations of input needed to produce them.



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Warnier/Orr diagrams show the processes and sequences in

which they are performed. Each process is defined in a

hierarchical manner.

It uses a set of brackets to show each level of the system.

To develop aWarnier/Orr diagram, the analyst works

backwards, starting with systems output and using output

oriented analysis.

WARNIERR-ORR DIAGRAM CONTINUED...



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Each bracket on the diagram (depending on how you

represent it, the character is usually more like a brace "{"

than a bracket "[", but we call them "brackets") represents

one level of hierarchy.

It is simply a nested group of sets and subsets shown as a set

of nested brackets.



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The step listed first is the first that will be executed (if thediagram reflects a process), while the step listed last is the last

that will be executed.

Within one level of hierarchy, the features listed are shown in

the order in which they occur.

Similarly with data, the data field listed first is the first that isencountered when looking at the data, the data field listed

last is the final one encountered.



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Repetition is indicated by placing a set of numbers inside

parentheses beneath the repeating set.

It occurs whenever the same set of data occurs over and over

again (for a data structure) or whenever the same group of

actions is to occur over and over again (for a processing

structure).



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The Exclusive OR symbol (the plus sign inside the circle)

indicates that the sets immediately above and below it are

mutually exclusive (if one is present the other is not).

It is the traditional "decision" process whereby a

determination is made to execute one process or

another.

It is also permissible to use a "negation bar" above an

alternative in a manner similar to engineering notation. The

bar is read by simply using the word "not."



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The concurrency operator is rarely used in program design

(since most languages do not support true concurrent

processing anyway), but does come into play when resolving

logical and physical data structure clashes.

Concurrency is one of the two advanced constructs used in

the methodology. It is used whenever sequence is

unimportant.



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The doubled bracket indicates that the set is recursive. Data

structures that are truly recursive are rather rare.

It is used to indicate that a set contains an earlier or a less

ordered version of itself.



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Say Good Afternoon

Welcome a guest

to your home

(1, G)

Greet the Guest

Take the guests

coat

AND

Show guest in

Its morning

Its afternoon

Its evening

OR

OR

Help the guest remove their coat

Hang the coat up

Say Good Morning

Say Good Evening



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It is a method for structured programming based on

correspondences between data stream structure and

program structure.

JSP was originally developed in the 1970s by IT consultantMichael A. Jackson and documented in his 1975 book

Principles of Program Design.

JSP is more straightforward than other structured methods,avoiding the leaps of intuition needed to successfully

program using, say, top-down decomposition.



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JSP uses semi-formal steps to capture the existing structure of

a program's inputs and outputs in the structure of the

program itself.

Jackson's major insight was that requirement changes are

usually minor tweaks to the existing structures. For a

program constructed using JSP, the inputs, the outputs, and

the internal structures of the program all match, so small

changes to the inputs and outputs should translate into

small changes to the program.

JSP CONTINUED...



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A single operation is drawn as box:

A sequence of operations is represented by boxes connected with

lines. In the example below, operation A consists of the sequence of

operations B, C and D.

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A



An iteration is again represented with joined boxes. In addition the

iterated operation has a star in the top right corner of its box. In the

example below, operation A consists of an iteration of zero or more

invocations of operation B.

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Selection is similar to a sequence, but with a circle drawn in the top

right hand corner of each optional operation. In the example,operation A consists of one and only one of operations B, C or D.

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Produce Table

Produce Table

Body

Produce Line *

Clear Line Produce Line Body Display Line

Compute Element*

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