Lag ,Total Float and Duration

Member for

21 years 8 months

There are no such thing as a universal rules for planning, the rules shall be used only as a guide/warning on possible errors but not to define them as definitive error. Some of these rules might prevent you from creating better models.



Say concrete placing activity takes 6 hours but curing shall start after the 4th hour; there is a necessary lag that is more than 50% the duration of predecessor. You can bypass such 50% requirement if model lag as an activity.



Say an activity takes 3 months, common in linear jobs; if you split the activity into separate activities then resource leveling might spread them apart instead of keeping the activity contiguous.



Float is a calculation, if the software can do the right calculation and the model is good it will be whatever it comes to be.

Member for

17 years 4 months

Hi Arun,

1. For SS+ Lag, the lag should not be more than half of  the predecessor duration. Always try to avoid FS+Lag.

2. Try to limit the construction activities in 21 days, to monitor & control it properly.

3. Total Float depends on the proper logic in the programme.

 

BR

Kannan