I'm offering a design solution for an enterprise level applications navigation system. Currently the user can navigate by drilling through a series of parent and child menus. There are up to 5 levels of navigation possible, each level displayed in a different view and up to 16 children in each view.
The desire is to move this system to a single page application. Normally I would look to see if the number of menu options could be reduced, but there's no time. I have a few solutions to consolidate the navigation and was hoping someone could offer a few more or insights.
Multilevel tree navigation A tree navigation could be displayed on the the page. This would be persistent and would need clear insets to distinguish between levels. My concern here would be given the number of option possible it might get difficult for the user to quickly see where they are in the application. Also having all the navigation visible complicates the ui.
Mega menu This could get real ugly with flyouts of 4 and 5 levels. The dexterity required to Handel flyouts off flyouts is undesirable. A variation could be handling up to 2 levels of flyouts navigation and deeper levels would be shown in a see more link which would take the user to a different view with the child links. However this breaks the SPA model.