Retained Logic, Progress Override and Actual Dates – The Official Site for Zümmer

Retained Logic, Progress Override and Actual Dates

There are many of articles regarding this topic on the internet. If you’re still not clear about the difference, below is an explanation presented as simply as possible.

In the illustration above, Activity B is assigned an Actual Start and Actual Finish date LATER than the Data Date. This condition is not considered “best practice” since there should be no Actual Dates later than the Data Date; however, this assignment is necessary to illustrate the difference between Actual Dates and Retained Logic. When there are no Actual Dates later than the Data Date, then Actual Dates and Retained Logic generally behave the same. The difference among the 3 options is reflected in the different Start and Finish dates for Activity C.

In Figure 1, using ACTUAL DATES, Activity C starts after the Actual Finish date for Activity B.

In Figure 2, using RETAINED LOGIC, Activity C ignores the Actual Dates of Activity B and starts after the Finish Date from Activity A.

In Figure 3, using PROGRESS OVERRIDE, since Activity B is “progressed” with Actual Dates, Activity’s C logic is “overridden” and therefore starts on the Data Date.

In summary, the method used to schedule the CPM network could have significant differences in determining the Start and Finish dates. Most contract specifications require the use of Retained Logic. There are many articles that can be found on the internet that cover this issue in greater detail to include effects on earned value and other properties.