Maximum Delay in Month

Arun,

This will depend on a number of things. The most obvious being whether or not you have changed the logic. Obviously doing this can affect the project by much more than a month in a month. Another thing will be your data date. Perceivably you might schedule this on 31 days. The most surprising reason that could cause the date to slip by greater than one month however, without adding any additional logic or increasing durations is in fact, reducing a duration on an activity with a SS relationship type.

Example - Consider a situation where you have three activities, each with a duration of 50 days. A, B and C. There is logic between each of these in the form of a FF relationship from A to B, and a SS relationship from B to C and prior to scheduling on, these activities are all perfectly aligned. Now imagine that activity A has been delayed by the full month in a month due to additional logic feeding this activity, be that 20, 30, 31 days etc dependant on calendars and data date movements. This change will thus move activities B and C by this same amount of time. Additionally, it is possible that on top of this movement of activity A, activity B will for some reason have a duration reduction from 50 to 20 days as part of the month end update (new information/reforecasting etc). This shortening of activity B will not have an affect on its finish date since that is still anchored by activity A's delayed finish date. It's start date however, will have to move to the right (assuming it does not already have an actual start). This delay to activity B's start will now impact activity C's as well and therefore it's finish date, which had already been delayed by the slippage of activity A. Ultimately, there has only been a month's delay on preceeding activities but other changes have caused activity C to be delayed by 60 days.

It's an uncommon scenario but one to be aware of.

Arun,

This will depend on a number of things. The most obvious being whether or not you have changed the logic. Obviously doing this can affect the project by much more than a month in a month. Another thing will be your data date. Perceivably you might schedule this on 31 days. The most surprising reason that could cause the date to slip by greater than one month however, without adding any additional logic or increasing durations is in fact, reducing a duration on an activity with a SS relationship type.

Example - Consider a situation where you have three activities, each with a duration of 50 days. A, B and C. There is logic between each of these in the form of a FF relationship from A to B, and a SS relationship from B to C and prior to scheduling on, these activities are all perfectly aligned. Now imagine that activity A has been delayed by the full month in a month due to additional logic feeding this activity, be that 20, 30, 31 days etc dependant on calendars and data date movements. This change will thus move activities B and C by this same amount of time. Additionally, it is possible that on top of this movement of activity A, activity B will for some reason have a duration reduction from 50 to 20 days as part of the month end update (new information/reforecasting etc). This shortening of activity B will not have an affect on its finish date since that is still anchored by activity A's delayed finish date. It's start date however, will have to move to the right (assuming it does not already have an actual start). This delay to activity B's start will now impact activity C's as well and therefore it's finish date, which had already been delayed by the slippage of activity A. Ultimately, there has only been a month's delay on preceeding activities but other changes have caused activity C to be delayed by 60 days.

It's an uncommon scenario but one to be aware of.

Delays might be a function of calendars.  If you delay a critical activity execution by one month and this put it into a winter season then it might become on hold several months after the winter, therefore delaying the completion of job.