Figure $1$: Communication diagram

$1\mathrm{.}2\mathrm{.}1$ Tell us whether the given communication diagram above is in good order to be

classified as data flow diagram and why?

$1\mathrm{.}2\mathrm{.}2$ In your own view what data flow diagram can be used for?

$1\mathrm{.}2\mathrm{.}3$ What is the importance of using communication diagram?

$1\mathrm{.}3$ What are the three goals of Work breakdown structure $($WBS$)?$