Program Hierarchy – Tracing Design Output to its Source

In computer programming:

Hierarchy is the arrangement of items where the items are given value in relation to each other.  All the items are either above, below, or at the same level as one another.  Computer programs with a hierarchical structure are organized into ranks where each item is subordinate to the item above it.  In a hierarchal structure there is one top level and a series of lower levels under it.  Hierarchy allows a programmer to build more and more complicated structures one on top of the other.

Hierarchy charts show how each item or task relates to each other.  They also show how the program manipulates input data.  Algorithms are used to determine a step by step process in which the input data is manipulated.  Algorithms are a list of instructions for the computer to execute, manipulating the input data to produce an output.  Once all steps in the algorithm are executed and an output is produced, the algorithm is terminated.

The input data to the algorithm can be a single input or multiple inputs depending on how the program and algorithm is written.  To make things easier to understand, a chart can be constructed explaining how the hierarchy structure is constructed and which algorithms will be used depending on the input data it receives.

Program hierarchy charts are organized much like a structure chart.  There are many levels, some higher than others and some below others.  Similar to when one constructs a structure chart, branching is a common practice when constructing program hierarchy charts.

In the real world:

Hierarchy exists in almost every facet of the real world.  Hierarchy is a structure that imposes a value on objects usually linking more valuable, bigger, or more powerful objects to lesser objects below them. 

In government, a hierarchal structure is prominent.  At the top sits the president, below him is the vice president, below him is the speaker of the house, etc.  In school systems, the superintendant is at the top, with the school board below him, below them are the schools principals, followed by vice principals, and teachers. 

Even in something as big as our universe there is hierarchy.  In relation to where we reside (the planet Earth), the top of our hierarchy is the observable universe, below that are local super clusters, in which the Virgo super cluster resides, inside that is the local galactic group, in which is our milky way galaxy, inside the milky way is our solar interstellar neighborhood, which is where our solar system resides, where Earth is the third planet from our sun.

Even simple file structure in a computer has a hierarchal structure.  Each hard drive that contains any data has a file structure system.  When you open your main hard drive (C Drive) inside are folders (Program Files, System Files, Applications, etc.), inside those folders are other folders and/or files.  In this case the C Drive would be at the top of the hierarchy with every file in the drive below it.  The hierarchy branches out as files are created and stored.