A milestone slip chart is a simple but very effective progress report.
On a weekly or monthly basis milestones are plotted on a grid to show when they are scheduled to occur. In the example 0 represents the start of the project or programme. In the baseline schedule milestone M1 is due to occur in week 2; M3 in week 5 and M3 in week 7.
At the end of the first week of work, all three milestones are on schedule, by the end of week two they are all running a week late. At the end of week three M1 finishes a week late and the other milestones are still running one week late.
In week four M2 is back on schedule but M3 is still running a week late. M2 finishes on time in week five but by week six M3 has been delayed a further week.
The progress dates can be easily transferred from a detailed schedule to this simple report which will be perfectly adequate for many stakeholders who only require high level progress information.