The flowchart is a means of visually presenting the flow of data through an information processing systems, the operations performed within the system and the sequence in which they are performed. In this lesson, we shall concern ourselves with the program flowchart, which describes what operations (and in what sequence) are required to solve a given problem. The program flowchart can be likened to the blueprint of a building. As we know a designer draws a blueprint before starting construction on a building. Similarly, a programmer prefers to draw a flowchart prior to writing a computer program. As in the case of the drawing of a blueprint, the flowchart is drawn according to defined rules and using standard flowchart symbols prescribed by the American National Standard Institute, Inc.
A flowchart is a graphic representation of how a process works, showing,
at a minimum, the sequence of steps. Several types of flowcharts exist: the
most simple (high level), a detailed version (detailed), and
one that also indicates the people involved in the steps (deployment or
When to use flow chart
A flowchart helps to clarify how things are
currently working and how they could be improved. It also assists in finding
the key elements of a process, while drawing clear lines between where one
process ends and the next one starts. Developing a flowchart stimulates
communication among participants and establishes a common understanding
about the process. Flowcharts also uncover steps that are redundant or
misplaced. In addition, flowcharts are used to identify appropriate team
members, to identify who provides inputs or resources to whom, to establish
important areas for monitoring or data collection, to identify areas for
improvement or increased efficiency, and to generate hypotheses about
causes. Flowcharts can be used to examine processes for the flow of
patients, information, materials, clinical care, or combinations of these
processes. It is recommended that flowcharts be created through group
discussion, as individuals rarely know the entire process and the
communication contributes to improvement.
Meaning of a flow chart
A flowchart is a diagrammatic representation that illustrates the sequence of operations to be performed to get the solution of a problem. Flowcharts are generally drawn in the early stages of formulating computer solutions. Flowcharts facilitate communication between programmers and business people. These flowcharts play a vital role in the programming of a problem and are quite helpful in understanding the logic of complicated and lengthy problems. Once the flowchart is drawn, it becomes easy to write the program in any high level language. Often we see how flowcharts are helpful in explaining the program to others. Hence, it is correct to say that a flowchart is a must for the better documentation of a complex program.
A high-level (also called first-level or top-down) flowchart shows the major steps in a process. It illustrates a "birds-eye view" of a process, such as the example in the figure entitled High-Level Flowchart of Prenatal Care. It can also include the intermediate outputs of each step (the product or service produced), and the sub-steps involved. Such a flowchart offers a basic picture of the process and identifies the changes taking place within the process. It is significantly useful for identifying appropriate team members (those who are involved in the process) and for developing indicators for monitoring the process because of its focus on intermediate outputs.
Most processes can be adequately portrayed in four or five boxes that represent the major steps or activities of the process. In fact, it is a good idea to use only a few boxes, because doing so forces one to consider the most important steps. Other steps are usually sub-steps of the more important ones.
The detailed flowchart provides a detailed picture of a process by mapping all of the steps and activities that occur in the process. This type of flowchart indicates the steps or activities of a process and includes such things as decision points, waiting periods, tasks that frequently must be redone (rework), and feedback loops. This type of flowchart is useful for examining areas of the process in detail and for looking for problems or areas of inefficiency. For example, the Detailed Flowchart of Patient Registration reveals the delays that result when the record clerk and clinical officer are not available to assist clients.
Deployment or Matrix Flowchart
A deployment flowchart maps out the process in terms of who is doing the steps. It is in the form of a matrix, showing the various participants and the flow of steps among these participants. It is chiefly useful in identifying who is providing inputs or services to whom, as well as areas where different people may be needlessly doing the same task. See the Deployment of Matrix Flowchart.
Each type of flowchart has its strengths and
weaknesses; the high-level flowchart is the easiest to construct but may not
provide sufficient detail for some purposes. In choosing which type to use,
the group should be clear on their purpose for flowcharting. The table below
entitled "Type of Flowchart Indicated for Various Purposes" gives some
indications, but if you're unsure which to use, start with the high-level
one and move on to detailed and deployment. Note that the detailed and
deployment flowcharts are time-consuming.
Guideline for drawing a flowchart
Flowcharts are usually drawn using some standard symbols; however, some special symbols can also be developed when required. Some standard symbols, which are frequently required for flowcharting many computer programs are shown.
It is not strictly necessary to use boxes, circles, diamonds or other such symbols to construct a flowchart, but these do help to describe the types of events in the chart more clearly. Described below are a set of standard symbols which are applicable to most situations without being overly complex.
Rounded box - use it to represent an event which occurs automatically. Such an event will trigger a subsequent action, for example `receive telephone call', or describe a new state of affairs.
Rectangle or box - use it to represent an event which is controlled within the process. Typically this will be a step or action which is taken. In most flowcharts this will be the most frequently used symbol.
Diamond - use it to represent a decision point in the process. Typically, the statement in the symbol will require a `yes' or `no' response and branch to different parts of the flowchart accordingly.
Circle - use it to represent a point at which the flowchart connects with another process. The name or reference for the other process should appear within the symbol.
Try to develop a first draft in one sitting, going back later to make refinements. Use the "five-minute rule": do not let five minutes go by without putting up a symbol or box; if the decision of which symbol or box should be used is unclear, use a cloud symbol or a note and move on.
To avoid having to erase and cross out as ideas develop, cut out shapes for the various symbols beforehand and place them on the table. This way, changes can easily be made by moving things around while the group clarifies the process.
Decision symbols are appropriate when those working in the process make a decision that will affect how the process will proceed. For example, when the outcome of the decision or question is YES, the person would follow one set of steps, and if the outcome is NO, the person would do another set of steps. Be sure the text in the decision symbol would generate a YES or NO response, so that the flow of the diagram is logical.
In deciding how much detail to put in the flowchart (i.e., how much to break down each general step), remember the purpose of the flowchart. For example, a flowchart to better understand the problem of long waiting times would need to break down in detail only those steps that could have an effect on waiting times. Steps that do not affect waiting times can be left without much detail.
Keep in mind that a flowchart may not need to include all the possible symbols. For example, the wait symbol ( ) may not be needed if the flowchart is not related to waiting times.
Once the flowchart has been constructed to represent how the process actually works, examine potential problem areas or areas for improvement using one or more of the following techniques.
Examine each decision symbol: Does it represent an activity to see if everything is going well? Is it effective? Is it redundant?
Examine each loop that indicates work being redone (rework): Does this rework loop prevent the problem from recurring? Are repairs being made long after the step where the errors originally occurred?
Examine each activity symbol: Is this step redundant? Does it add value to the product or service? Is it problematic? Could errors be prevented in this activity?
Examine each document or database symbol: Is this necessary? Is it up to date? Is there a single source for the information? Could this information be used for monitoring and improving the process?
Examine each wait symbol: What complexities or additional problems does this wait cause? How long is the wait? Could it be reduced?
Examine each transition where one person finishes his or her part of the process and another person picks it up: Who is involved? What could go wrong? Is the intermediate product or service meeting the needs of the next person in the process?
Examine the overall process: Is the flow logical? Are there fuzzy areas or places where the process leads off to nowhere? Are there parallel tracks? Is there a rationale for those?