Note: Some options and features may vary from the article below based on your CS Project package.
A baseline is, in effect, a marker of the original location of your activity bars prior to changes in start dates and /or durations. This allows comparison to be made between the original sequence of events and time periods and the actual (as-built) program of works.
Once you are happy with your programme, the scheduled activities can be stored as a baseline using Progress – Baseline – Store from the CS Project Professional menu bar, or Progress – Store Baseline in CS Project Planning menu bar.
In CS Project Professional, multiple baselines can be stored and any two displayed at one time. The baselines are typically displayed as a black line underscoring the original activity.