The hierarchy shows the relationship of various units. It is important in the design phase of a component or system. It shows:

• Structure: Hierarchy shows the inner-composition of an item or idea.
• Organization: It shows the components of an item and how they are bonded together.
• Classification: An item at the top shows the classification of items below it.

Usually, a hierarchy is represented by a chart. Common examples include Business, Photo, Company, City, Market, IT, Corporate, Human Resource, School, Financial, Team, Police, Hospital, and Sales Organization Charts. This long list itself tells us that everything can be hierarchical.

It classifies the items or components. Our knowledge is classified data. Using a hierarchy, we can change the way people think about a concept. A hierarchy conveys:

• Intention: It shows the intent of the total structure or concept.
• Knowledge: It describes knowledge; or knowledge comes from classification.

There may be more than one way to depict a system or concept. Consequently, the details and depth of the resulting hierarchy may vary. Mainly it depends on where the stress is and what is the point of view:

• Stress: Stress means what you want to convey about the item.
• Point of View: Refers to the angle you view the object. Functional and structural hierarchies are best examples. In a photo collection, you can have chronological or person (family) views.

This is an important fact that should be fine-tuned by considering the target audience. Normally there is no problem having more than one hierarchical representation, each describing a different stress or point of view.

When it is required to analyze or modify something - it gives a bird's-eye view of the problem. Use it when you want to quickly grasp the totality and to learn about it. Hierarchy analysis should be used for:

• System Analysis: Suppose you have a complex problem at hand and need to find the best solution. You have to split/componentize it in a hierarchical way, give a weight (cost estimation/resource estimation) for each node, and calculate the optimal solution based on the optimal weight.
• System Enhancements: When you need to modify or revolutionize an existing system, you need the existing structural and functional hierarchy to suggest modifications mapped to a new, better hierarchy.

There are two types of hierarchy charts to describe organizational structure:

Static Hierarchy Charts

Static charts can be created by diagramming tools (like Microsoft Visio) or drawing tools. The end point is that you save the chart drawn to an image file. Issues with static charts include:

• Static behavior: It cannot have dynamic (hyperlinking or interactive) behavior from a user point of view.
• Possibility of expiry: Static hierarchy charts may expire quickly when the underlying data changes. It is difficult to redraw them each time.
• Drawing effort: It is tedious to manually determine the size, font, and position of nodes.

Dynamic Hierarchy Charts

Dynamic charts have a programming scenario. Once used in a computer program or website, it provides the user with powerful features powered by live data (e.g., from a database). Advantages include:

• Dynamic behavior: They are interactive. Users can expand/collapse, zoom, see tooltips, and navigate to more details.
• Runtime Data (Data Independence): It takes live data from the source. The data can change irrespective of chart settings.
• Automatic drawing: It automatically computes layouts depending on the volume of data.

These advantages are provided by chart-specific features like resizability, rich tooltips, smart layouts, and automatic sub-charts. Unifosys Chart4.NET is a powerful dynamic charting component specifically designed for .NET web and desktop developers.

Not many options are available on whom to be assigned the charge (on a sub-hierarchy):

• Sub-expert: An expert on the subject of the sub-hierarchy is required. It will cause a better detailed design and execution.