Phlegm originates from the lungs. It is different from the mucus that is produced in the nasal passages. A common cause of phlegm is post nasal drip which is a symptom of sinus infections, colds, flu and inhalation of irritants. The diagnosis of the underlying condition could be made from the color of the phlegm.
A flow chart is a type of diagram representing a process using different symbols containing information about steps or a sequence of events. Each of these symbols is linked with arrows to illustrate the flow direction of the process.
1 Define the required tasks and put them down in an ordered (sequenced) list. 2  Create a flowchart or other diagram showing each task in relation to the others. 3  Identify the critical and non-critical relationships (paths) among tasks. 4  Determine the expected completion or execution time for each task.