The IPO ModelThe IPO Model

Input – Process - OutputInput – Process - Output

I = InputI = Input Input is something from the external Input is something from the external

environment that is fed into the system. environment that is fed into the system.

In an information system, the inputs In an information system, the inputs may be raw data "captured" in some may be raw data "captured" in some way or pre-existing data which has been way or pre-existing data which has been provided by an external system. provided by an external system.

In either case, the data input is provided In either case, the data input is provided by an by an external entity.external entity.

P = ProcessP = Process The transformation process is the most The transformation process is the most

important element of a system.important element of a system.

The process accepts the inputs into the The process accepts the inputs into the system and performs some type of system and performs some type of operation on it which transforms it into operation on it which transforms it into some other state. In the simplest of terms, some other state. In the simplest of terms, the process is at the heart of any system. the process is at the heart of any system.

In a computerised information system, the In a computerised information system, the process is normally the storage, retrieval process is normally the storage, retrieval and modification of data which is and modification of data which is accomplished by hardware and software. accomplished by hardware and software.

O = OutputO = Output Output from the system which is the result Output from the system which is the result

of processing the input. of processing the input.

Without output, a system has no link back Without output, a system has no link back into it's external environment. into it's external environment.

Output of an information system may be Output of an information system may be reports generated by an information system, reports generated by an information system, or a picture on a computer monitor, or even or a picture on a computer monitor, or even data that is fed into another external data that is fed into another external system.system.

The IPO ModelThe IPO Model

INPUT Data and Processing

OUTPUT

Your analysis starts here

The requirements of the Output, more than anything else, will determine the requirements of the System.

Steps to complete an IPO Steps to complete an IPO ModelModel

StepsSteps1.1. Read and understand the problemRead and understand the problem2.2. Identify the outputsIdentify the outputs

Pick intrinsic variable names that represent the Pick intrinsic variable names that represent the outputoutput3.3. Decide what data Decide what data (the inputs) (the inputs) is required in is required in

order to get the required outputorder to get the required output Sometimes these will be given to you, sometimes not, Sometimes these will be given to you, sometimes not,

which means you may need to invent inputs. which means you may need to invent inputs. 4.4. Once you have the outputs and the inputs you Once you have the outputs and the inputs you

need to determine how the inputs can be need to determine how the inputs can be transformed into the required outputs. This is a transformed into the required outputs. This is a dynamic process which may mean you need to dynamic process which may mean you need to continually return to the previous steps. continually return to the previous steps.

ExampleAnalysis for CelsiusToFahrenheit

Program:

Input degrees Celsius

ProcessF = C * 9/5 + 32

Output degrees Fahrenheit

What output/s are require?What output/s are require?

Problem StatementProblem Statement

A student's final grade for a course is A student's final grade for a course is a weighted average of two tests, a a weighted average of two tests, a final exam, and four projects. Each final exam, and four projects. Each test is worth 15%, the final is worth test is worth 15%, the final is worth 30%, and the projects are worth a 30%, and the projects are worth a total of 40% (10% each). Given a total of 40% (10% each). Given a student's grades for all of these student's grades for all of these assignments, calculate the final score. assignments, calculate the final score.

What input/s are require?What input/s are require?

Problem StatementProblem Statement

A student's final grade for a course is A student's final grade for a course is a weighted average of two tests, a a weighted average of two tests, a final exam, and four projects. Each final exam, and four projects. Each test is worth 15%, the final is worth test is worth 15%, the final is worth 30%, and the projects are worth a 30%, and the projects are worth a total of 40% (10% each). Given a total of 40% (10% each). Given a student's grades for all of these student's grades for all of these assignments, calculate the final score. assignments, calculate the final score.

What process/es are What process/es are require?require?

Problem StatementProblem Statement

A student's final grade for a course is A student's final grade for a course is a weighted average of two tests, a a weighted average of two tests, a final exam, and four projects. Each final exam, and four projects. Each test is worth 15%, the final is worth test is worth 15%, the final is worth 30%, and the projects are worth a 30%, and the projects are worth a total of 40% (10% each). Given a total of 40% (10% each). Given a student's grades for all of these student's grades for all of these assignments, calculate the final score. assignments, calculate the final score.

Problem StatementProblem Statement A student's final grade for a course is a weighted average of two tests, a A student's final grade for a course is a weighted average of two tests, a final exam, and four projects. Each test is worth 15%, the final is worth final exam, and four projects. Each test is worth 15%, the final is worth 30%, and the projects are worth a total of 40% (10% each). Given a 30%, and the projects are worth a total of 40% (10% each). Given a student's grades for all of these assignments, calculate the final score. student's grades for all of these assignments, calculate the final score.

InputInput ProcessProcess OutputOutputGet Result of Test1Get Result of Test1Get Result of Test2Get Result of Test2Get Result of Get Result of FinalExamFinalExamGet Result of Project1Get Result of Project1Get Result of Project2Get Result of Project2Get Result of Project3Get Result of Project3Get Result of Project4Get Result of Project4

1.1. Calculate FinalScoreCalculate FinalScore2.2. FinalScore = (Test1 + FinalScore = (Test1 +

Test2) * 15/100 + Test3 * Test2) * 15/100 + Test3 * 30/100 + (Project1 + 30/100 + (Project1 + Project2 + Project3 + Project2 + Project3 + Project4) * 40/100 Project4) * 40/100

FinalScoreFinalScore

Design ExercisesDesign Exercises1. Consider a student file that contains the following data 1. Consider a student file that contains the following data fields:fields: First Name Last Name Course Grade First Name Last Name Course Grade

Would this set of data be suitable and sufficient to use to test each of Would this set of data be suitable and sufficient to use to test each of the following programs? Explain why or why not.the following programs? Explain why or why not.

A program that prints a list of SDD studentsA program that prints a list of SDD students A program that prints a list of students nearly failing - those with a grade is less A program that prints a list of students nearly failing - those with a grade is less

than 50%than 50% A program that prints a list of student on the Principal’s listA program that prints a list of student on the Principal’s list A program that prints a list of students from ParramattaA program that prints a list of students from Parramatta A program that prints a list of female students.A program that prints a list of female students.

2. Construct an IPO chart for a program that gives an 2. Construct an IPO chart for a program that gives an employee $50 bonus for every 500 items sold in a week.employee $50 bonus for every 500 items sold in a week.

3. Construct an IPO chart for a program that will output a 3. Construct an IPO chart for a program that will output a student's grading based on letter grades (A, B, C, D, or F) in student's grading based on letter grades (A, B, C, D, or F) in five courses.five courses.

2 * IPO Examples2 * IPO ExamplesInput Processing Output

original number 1. calculate the squared value by multiplying the original number by itself

2. display the squared value

squared value

Input Processing Output

state1 salesstate2 salescommission rate

1. enter state1 sales, state2 sales, and commission rate2. calculate the total commission by adding the state1 sales to the state2

sales, and then multiplying the result by the commission rate3. display the total commission

commission

Describe what these two IPO Describe what these two IPO models are doing…models are doing…

2 more IPO Examples2 more IPO ExamplesInput Processing Output

SalesCommission rate

1. Enter the sales and Commission rate2. Calculate the commission rate by multiplying sales time Commission rate 3. Display the Commission rate

Commission Rate

Describe what these two IPO Describe what these two IPO models are doing…models are doing…

Input Processing Output

Original number 1. Enter the Original Number2. If the original number is less than or equal to zero then display an error message, otherwise calculate the squared value by multiplying the Original number by itself. 3. Display the squared value

Squared value