Software Development

  Assignment 2 Guide

Design Phase - Define the Data in Detail

Introduction

The Assignment

a. Define the Data in Detail

Introduction

Objectives

This guide  will help you to: -  

·   define the data in detail for assignment 2

You should print out the following two assignment documents.

Assignment Scenario

Assignment 2: Designing the Program

As with assignment 1, assignment 2 is concerned with the Lawnsword Garden Design Company.  

This assignment is where you will create a detailed program design from the specification you produced in assignment 1. The result should be a set of documents which any other programmer could use to produce your program.

The documentation you need to produce for assignment 2 is listed below.

Task a. Define the data in detail

In order to complete Assignment 2 Task a, you need to define the data in detail.  You must define what data will be input, stored and output, and decide what format this data will have.

You have already outlined the inputs, outputs and stored data in your assignment 1.  Now you must

·   Specify the inputs in detail and their format

·   Specify the outputs in detail and their format

·   Specify the stored data in detail and their format

Have a look at your documentation for Assignment 1 Task g. You should have listed the inputs, outputs and stored data.  i.e. 

Inputs:-  

• the length of  the rectangular lawn (m) 

• the width of  the rectangular lawn (m) 

etc....

Outputs:-  

• the amount of lawn seeds (grams)

• the number of bags of lawn seeds

etc....

Stored Data:-  

• the amount of lawn seeds that cover 1 square meter (grams)

• the amount of lawn seeds in a bag (grams)

etc....

So how are we going to be more detailed about all of this?

We have to specify the format of the data - it's data type.  As an example, is the input for the length of  the rectangular lawn going to be a number or character data?
What about the amount of lawn seeds, will it be a whole number or something else?  And so on.

Datatypes

What kind of data can we have?  We can have numerical data types - whole numbers or numbers with decimal parts.  We can have character and string data types - like names or postcodes etc.  Let's give these data types the names that visual basic uses:-

Integer - means a whole number like 10, -2, 1000

Single - means a number with a decimal part like 0.3, -10.234 etc.

Character - means data like the keyboard characters you press. For example,  a, b to z and the digits 0, 1 ...9 on a keyboard are actually characters.

String - means a set of characters like "Fred", "SE206EE" etc.

So for each input, output and stored data, you should create a table similar to the one below:-

Input Data	Data Type	VB Data Type	Variable Name	Min/Max	Explanation
Rectangular Lawn Length (m)	floating point number	single	rectLawnLength	The number must be larger than 0.  Max number of digits will be 4. So max number will be 9999	A lawn length measurement may have a decimal part.  E.g. 4.3m.
Rectangular Lawn Width (m)	floating point number	single	rectLawnWidth	The number must be larger than 0.  Max number of digits will be 4. So max number will be 9999	A lawn width measurement may have a decimal part.  E.g. 3.3m.
etc...

Here is one for the output data.

Output Data	Data Type	VB Data Type	Variable Name	Min/Max	Explanation
The amount of lawn seeds	floating point number	single	amountLawnSeed	The number must be larger than 0.  Max number of digits will be 4. So max number will be 9999	This data type is likely to have a decimal part  E.g. 300.7 grams
The number of bags of lawn seeds	floating point number	single	numBagsLawnSeed	The number must be larger than 0.  Max number of digits will be 4. So max number will be 9999	This data type is likely to have a decimal part  E.g. 3.5 bags
etc...

Here is one for the stored data.

Stored Data	Data Type	VB Data Type	Variable Name	Min/Max	Explanation
The amount of lawn seeds that cover 1 square meter	Whole number	integer	lawnSeedCoverage	The number must be larger than 0.  Max number of digits will be 3, so max number will be 999	This data type is likely to be a whole number  E.g. 30 grams
The amount of lawn seeds in a bag	Whole number	integer	lawnSeedinBag	The number must be larger than 0.  Max number of digits will be 3, so max number will be 999	This data type is likely to be a whole number  E.g. 1000 grams
etc...

   

Your Task

Now it's your turn to create your tables:-

Please ensure you write your name in the document header. The structure of your document should be as follows:-

 Assignment 2: Designing the Program

      Task a: Defining the data in detail

Here you should explain what your input table is about

Insert your input table

Here you should explain what your output table is about

Insert your output table

Here you should explain what your stored data table is about

Insert your stored data table

Have you finished all the tasks and handed them in?  

If so - well done.