The HIPO diagram (hierarchical input-output) is a combination of two organized methods for analyzing the system and providing documentation tools. The HIPO model was developed by IBM in 1970.
The HIPO diagram is a hierarchy of modules in the software system. The analyst uses the HIPO chart to get a general idea of the functions of the system. It breaks the functions into subfunction in hierarchical order. It depicts the functions performed by the system.
HIPO diagrams are good for documenting purposes. Their graphic representation allows designers and managers to get a visual idea of the structure of the system.
HIPO diagrams
Unlike the IPO diagram (Input Process Output), which displays the control flow and data in the module, Hipo does not provide any information about the data stream or control flow.
IPO schedule
example
Both parts of the HIPO diagram, the hierarchical representation and IPO diagram are used to design the software structure, as well as for documentation on them.
Structured English
Most programmers do not know about the overall picture of the software, so they rely only on what their managers say to them. Responsibility for providing accurate information to programmers to develop accurate, but fast code lies with the highest management of software.
Other forms of methods that use graphs or diagrams can sometimes be interpreted differently by different people.
Therefore, software analysts and developers come up with tools such as structured English. This is nothing more than a description of what is required for coding and how to encode it. Structured English helps the programmer write an unmistakable code.
Other forms of methods that use graphs or diagrams can sometimes be interpreted differently by different people. Here, both structured English and the pseudo -cod are trying to eliminate this gap in understanding.
Structured English – this uses simple English words in the paradigm of structured programming. This is not the final code, but a kind of description of what is required for coding and how to encode it. Below are some structural programming tokens.
If-teen -else,
Do-While-tontil
Analyst uses the same variable and data name that are stored in the data dictionary, which greatly simplifies the spelling and understanding of the code.
example
We use the same example of customer authentication among online purchases. This procedure for authentication of the client can be written in structured English as:
Enter Customer_name
Seek Customer_name in Customer_name_db File
Run Customer_name Found then
Call Procedure user_password_authenticate ()
Else
Print Error Message
Call Procedure New_customer_request ()
Endif
The code written in structured English is more like everyday conversational English. It cannot be implemented directly as a software code. Structured English does not depend on the programming language.
Pseudo-code
The pseudo -code is written closer to the programming language. It can be considered as an extended programming language, full of comments and descriptions.
The pseudo -code avoids the announcement of variables, but they are written using some real design of the programming language, such as C, Fortran, Pascal, etc.
The pseudocode contains more programming details than structured English. It provides a method for performing a task, as if a computer performs a code.
example
Program for printing Fibonacci to N numbers.
Void Function Fibonacci
Get Value of N;
Set Value of a to 1;
Set Value of B to 1;
Initialize i to 0
for (i = 0; i <n; i ++)
{
if a grreater than b
{
Increase b by a;
Print b;
}
Else IF B Greater than a
{
Increase a by b;
Print a;
}
}
Solution tables
The decisions table presents the conditions and relevant actions that must be taken to eliminate them, in a structured tabular format.
This is a powerful tool for debugging and preventing errors. This helps to group such information into one table, and then, combining tables, provides simple and convenient decision -making.
Creating a solution table
To create a solution table, the developer must perform four main steps:
Determine all possible conditions for solving
Determine actions for all identified conditions
Create the most possible rules
Determine the action for each rule
Solution tables should be checked by end users and recently can be simplified by excluding duplicate rules and actions.
example
Let’s look at a simple example of a day of problems with the Internet connection. We will begin by identifying all the problems that may arise when starting the Internet, and their corresponding possible solutions.
Model of entity-attitude
The Entity-Relationship model is a type of database model based on the concept of the essences of the real world and the relationship between them. We can display the scenario of the real world to the model of the ER database. The ER model creates a set of objects with their attributes, a set of restrictions and connections between them.
The ER model is best used for conceptual database design. The ER model can be presented as follows:
ER model
The essence is the essence in the ER model – this is the essence of the real world, which has some properties called attributes. Each attribute is determined by the corresponding set of values called the domain.
For example, consider the school database. Here a student is an essence. The student has various attributes, such as the name, identifier, age and class, etc.
Relations – a logical connection between entities is called relationships. Relations are displayed with entities in various ways. Display cardinals determine the number of associations between two objects.
Picture of cardinality:
one to one
One to many
Much to one
Many to many
The essence is the essence in the ER model – this is the essence of the real world, which has some properties called attributes. Each attribute is determined by the corresponding set of values called the domain.
For example, consider the school database. Here a student is an essence. The student has various attributes, such as the name, identifier, age and class, etc.
Relations – a logical connection between entities is called relationships. Relations are displayed with entities in various ways. Display cardinals determine the number of associations between two objects.