Though projects use certain charting techniques like Bar, Milestone, Gantt to represent project schedules, they lack visualization of inter dependencies between different activities.
By constructing schedule networks, we can get inter dependencies between activities and can develop master schedule plan that provides up-to date schedule information about the project. Schedule network analysis is a technique that generates the project schedule.
In short, Schedule Network Analysis is the technique of identifying early and late start dates, as well as early and late finish dates, for the uncompleted portions of project schedule activities. 
It employs a schedule model and various analytical techniques, such as critical path method, critical chain method, what-if analysis, and resource leveling to calculate various project schedule information.
Schedule network provides:
* dependencies between activities,
* project completion date,
* analysis of the early and late start and finish dates,
* analysis of applying leads and lags,
* analysis of slippage in project schedule
* analysis of scheduled start and finish dates for the uncompleted portions of project schedule activities
* graphical representation of the whole project from start to finish (master schedule plan)
We need to make following considerations before applying any of the analytical techniques
* adjustment should be made on any loops or open ends in schedule network for accurate calculation
* some network paths may have points of path convergence or path divergence that can be identified and used in schedule compression analysis or other analyzes
. PMBOK® Guide – 3rd edition