What is a hierarchy chart?

The hierarchy chart is a graphical representation that is used to represent the relationship between various modules or systems in an organization. In programming, a hierarchy chart is used for representing an organizational framework. The hierarchy charts can also be utilized to show an organization’s reporting structure. In such a hierarchy chart, the President is at the top, the Vice Presidents are on the next level which is lower than its predecessor, and so forth.

Within the context of a software program, it indicates the relationship among modules (or capabilities). The design team members create hierarchy charts to represent the relationship between modules in an application.

A hierarchy chart represents the breakdown of a framework to its most minimal reasonable parts. It represents a hierarchical relationship using square shapes (which represent the various modules in a framework) and lines (which represent the association among the modules). 

These charts are utilized to introduce all parts in a framework and organize them. A chain of command outline begins with the framework’s name as a solitary substance and a top-down list of various elements within the framework.

Concept of the hierarchy chart

The hierarchy chart is a structure chart that is used to represent the control information and data that gets exchanged between the modules. In a hierarchy chart, a rectangular symbol is used to represent each module. An arrow sign with an open circle at the source end is used to represent each data pair or flow of data.

The workflow, code selection and logical structures of the code are not shown in the structure chart. However, some creators and designers include transaction hubs in a control module by identifying high-level case structures.

Designers create a program using a hierarchy chart in the same way that an architect creates a plan for a house. Each of the functions or modules are placed at their correct positions and also the flow of data between the various modules is also listed.

An example of the hierarchy chart for a software application is discussed in the last section of this article.

How to create Hierarchy chart to represent an organization's structure?

• Find the most essential entity of the system. For example, the CEO is in the highest position in an organization.
• Choose the components for the second level, third level, fourth level, and so on. List them down.
• Once you list them down in the hierarchy chart, connect them to show the relationship between entities and their parts.
• If one wants to add some more information, one can add them to the chart.
• Use themes available to color the chart in order to make it visually attractive.
• Download the hierarchy chart in an available format like png, jpg, etc., in order to use it in presentations and documents.

Components of a Hierarchy chart

1. Module - It represents a task or a process. A module can be a

• Sub Module: It is a module that is actually a part of another module.
• Control Module: It is a module responsible for coordinating several sub-modules.
• Library Module: It is a module that can be called and reused by other modules.

2. Conditional Call denotes a control module that has the ability to select any sub-module based on a set of circumstances.

3. Loop - The loop refers to the repeated execution of a set of modules.

4. Data Flow - The flow of data between modules is represented by data flow. A directed arrow with an empty circle at the end represents it.

5. Control Flow - It depicts the control flow between the modules. A directed arrow with a filled circle at the end is also used to express it.

6. Physical Storage- It is a storage space for all of the information.

What is the purpose of the hierarchy chart?

• The hierarchy chart or the hierarchy diagram represents the breakdown of the system to its lowest level. It uses a top-down design tool using lines and rectangles. The rectangles denote the entities or component modules. The lines denote a link between two entities or modules. The hierarchy chart starts with the topmost entity represented at the root of the tree-like structure and lists down all other entities in several levels. The hierarchy chart can be used for illustrating hierarchical classification of modules corresponding to a software application. In general, it can be used to organize concepts for better clarity.

• Common uses of hierarchy chart:

1. Educational purpose: Hierarchy charts have been used to visualize classification of concepts in various subjects. For example, a biology teacher uses a hierarchy chart while describing the digestive system.
2. Business purpose: When one wants to observe the working of a system in a business area, a hierarchy chart can be used. It depicts the flow of data and where the products are utilized, and how the products are sold to the marketplace.

The hierarchy charts are useful in various domains like in software application development, educational and learning charts, business marketing and development, organizational charts like the ones that depict the working structure of employees or the working of an organization towards the completion of a project. It is also used in Civil engineering for depicting the flow of traffic on roads.

Example of hierarchy chart

Let us consider the example of a software application like an online shopping website for which the hierarchy chart is designed. The online shopping website is an abstract entity. While planning an online shopping website, one needs to take care of all the aspects of the structure and the mental representation of all the abstractions. The figure given below gives a detailed explanation for an online shopping website.

Common Mistakes

It is important to note that a hierarchy chart does not represent the logical flow within the modules. A hierarchy chart is the structural representation of an organization or a system's components. It is not necessary to cover the rational elements in the hierarchy chart. It is essential to understand the position of each component and its connections. Also, the following mistakes will result in an incorrect chart:

• Misjudging hierarchy chart positions
• Not aligning structure with strategy
• Making hierarchy charts using outdated tools

Context and Applications

This topic is important for both graduation and post-graduation, especially for:

• Masters of Science in Computer Science
• Bachelors of Science in Information Technology
• Bachelors of Science in Information Science
• Masters of Science in Software Engineering

Related Concepts

• Programming Fundamentals
• Hippo Diagram
• Work Breakdown structure

Practice Problems

Q1. What is another name of the hierarchy chart?

1. DFD               
2. Sample chart
3. Structure chart
4. System context diagram

Correct option: (3)

Explanation: Hierarchy chart is also known as a structure chart.

Q2. What is the complete form of DFD?

1. Data Flow Diagram.
2. Design Flow Diagram.
3. Data fulfill Diagram.
4. Data fill Data

Correct option: (1)

Explanation: The complete form of DFD is the "Data Flow Diagram." It depicts the flow of data in the system.

Q3. Which is not part of the hierarchy chart symbol?

1. module
2. physical storage
3. Data flow
4. Attributes

Correct option: (4)

Explanation: Attribute does not come in hierarchy chart symbol.

Q4. In a hierarchy chart, which of the following symbol is responsible for control flow?

1. An arrow
2. A curved arrow
3. An arrow with an empty circle
4. An arrow with a filled circle

Correct option: (4)

Explanation: An arrow expresses the relationships among the components. A curved arrow represents the loop. The data flow is shown by an arrow with an empty circle, whereas the instruction flow is represented by an arrow with a filled circle.

Q5. A hierarchy chart is used to show:-

1. Organization structure

2. To represent data

3. To represent personal information

4. None

Correct option: (1)

Explanation: Hierarchy chart illustrates the organization structure of various modules of a system.