Best Program to Make Workflow Diagrams

This circle diagram sample was redesigned from the Wikimedia Commons file: Research cycle.png. "Some of the basic elements of the scientific method, arranged in a cycle to emphasize that it is an iterative process." [commons.wikimedia.org/ wiki/ File:Research_ cycle.png]
This file is licensed under the Creative Commons Attribution 2.0 Generic license. [creativecommons.org/ licenses/ by/ 2.0/ deed.en]
"The scientific method is a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry must be based on empirical and measurable evidence subject to specific principles of reasoning. ...
Four essential elements of the scientific method are iterations, recursions, interleavings, or orderings of the following:
(1) Characterizations (observations, definitions, and measurements of the subject of inquiry).
(2) Hypotheses (theoretical, hypothetical explanations of observations and measurements of the subject).
(3) Predictions (reasoning including logical deduction from the hypothesis or theory).
(4) Experiments (tests of all of the above)...
A linearized, pragmatic scheme of the four points above is sometimes offered as a guideline for proceeding:
(1) Define a question.
(2) Gather information and resources (observe).
(3) Form an explanatory hypothesis.
(4) Test the hypothesis by performing an experiment and collecting data in a reproducible manner.
(5) Analyze the data.
(6) Interpret the data and draw conclusions that serve as a starting point for new hypothesis.
(7) Publish results.
(8) Retest (frequently done by other scientists).
The iterative cycle inherent in this step-by-step method goes from point 3 to 6 back to 3 again." [Scientific method. Wikipedia]
The circle diagram example "Research cycle" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Target and Circular Diagrams solution from the Marketing area of ConceptDraw Solution Park.
www.conceptdraw.com/ solution-park/ marketing-target-and-circular-diagrams

This arrow loop cycle diagram sample was created on the base of the figure illustrating the webpage "Exploratory Advanced Research Program Hand-Off Workshops" from the US Department of Transportation - Federal Highway Administration (FHWA) website. "The FHWA’s research and technology innovation life cycle illustrates that research and technology development are not insular activities, but integrated processes that together constitute a system.
Following general workshop discussion, a number of common issues emerged among the groups. These centered around the research life cycle, communicating the value of exploratory advanced research, and continued project funding. It was felt that there is a general need to better describe the research and deployment cycle specific to highway transportation and possibly to highway research fields, such as materials or system planning. Research life cycle diagrams show a very linear, chronological process but it is not necessarily that way in reality." [fhwa.dot.gov/ advancedresearch/ pubs/ 11034/ ]
The arrow loop diagram example "Innovation life cycle" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Target and Circular Diagrams solution from the Marketing area of ConceptDraw Solution Park.
www.conceptdraw.com/ solution-park/ marketing-target-and-circular-diagrams