Guild of Project Controls: Compendium | Roles | Assessment | Certifications | Membership

Tips on using this forum..

(1) Explain your problem, don't simply post "This isn't working". What were you doing when you faced the problem? What have you tried to resolve - did you look for a solution using "Search" ? Has it happened just once or several times?

(2) It's also good to get feedback when a solution is found, return to the original post to explain how it was resolved so that more people can also use the results.

Broken Team Lag

13 replies [Last post]
Rafael Davila
User offline. Last seen 11 hours 9 min ago. Offline
Joined: 1 Mar 2004
Posts: 5169

In the following example tem 2 lag is broken after resource leveling. Is there a field to identify broken team lag?

In adittion to a field good for filtering out a warning on the schedule report would help.

Broken-Team-Lag

Best Regards, Rafael

Replies

Rafael Davila
User offline. Last seen 11 hours 9 min ago. Offline
Joined: 1 Mar 2004
Posts: 5169

GIF-Thank-You

Rafael,

in the new version the bug is fixed.

This feature was added for our customers (one of Gazprom branches) that did not require trucks leveling. We warned them that with leveling it will not work properly.

To simulate the real work it is necessary to add variable productivity. In this case truck productivity depends on the activity volume. With the increase of volume done the distance becomes larger and productivity lower. We did not develop this feature yet.

Rafael Davila
User offline. Last seen 11 hours 9 min ago. Offline
Joined: 1 Mar 2004
Posts: 5169

In the following model, based on my reconstruction of Vladimir schedule [Sat, 2022-07-02 04:49], after adding an activity loaded with some trucks I got the following.

2022-07-02-13-10-04-Activity-Gantt-Lag-Calendar-11-Lag-Calendar

  • Activity 2 delays execution of Team 2
  • Work above 40 continues during week 2 but with only 4 trucks and not with the required 6 as they are busy elsewhere. The production rate is not adjusted to account for a longer distance, to keep it 2 additional trucks are required.
  • Team 2 and Team 3 are scheduled at the same time but each team requires a digging crew for it to be feasible. Without any warning this model misses this requirement.

Definitively I have a preference to create new activities for segments with the different soil or some other conditions that impact productivity. In addition I have a preference to use multi-resources and assign productivity at the multi-resource level.

It is not unusual for earthworks among adjacent construction segments to require very different crews. It might be Segment requires borrow material, it might be the Segment is cut to fill with no haul and no trucks are required, it might be the Segment is a cut to waste that requires less haul distance. Crew composition will be different as well as the production rates.

hoover thumbnail, click and zoom for a better view - please note that the resource loading might be missing some resources as this model is for illustration only

Activity-Gantt-Borrow-Pit-1-Road-Construction-Activitiespng-Page1png-Page1 

Rafael Davila
User offline. Last seen 11 hours 9 min ago. Offline
Joined: 1 Mar 2004
Posts: 5169
  • we usually create new activities for segments with the different soil or some other conditions that impact productivity.

Sure, I was more into testing this functionality.

Going back to my sample model:

2022-07-01-19-45-34-Activity-Gantt-Lag-Calendar-3-Lag-Calendar

  • Activity volume is 100.
  • Team one executes 50 units of volume.
  • Then team 3 starts before the required 75 units volume lag without any warning.
  • For Strict Links there is a warning when condition is not met, the warning is shown on the schedule run reports but not on the links table as I would like it to be. While the condition is not always enforced it can help the scheduler to get it to happen. There is value for the Strict Links functionality as long as there is a warning telling you which link was not enforced for you to make the schedule adjustments. But minimal lag is always respected, breaking minimal lag should never be allowed.
  • I am missing something?

Rafael,

we usually create new activities for segments with the different soil or some other conditions that impact productivity.

Usually we create and assign activity types and reference-books where resource crews and productivity for activities of different types are stored.

If reference-books were created then it is sufficient to enter activity type and activity volume and everything else can be loaded from the reference-books automatically (resource crews, resource productivity, material requirements, costs, etc.).

So activities are of the same type if they share most characteristics.

Rafael Davila
User offline. Last seen 11 hours 9 min ago. Offline
Joined: 1 Mar 2004
Posts: 5169

But in my model for the 3rd segment crew productivity is reduced due to different work conditions and still more trucks are required to keep pace with a longer distance while productivity is reduced.

Yes, it does not make sense. Having only one remaining crew that is required in all three teams means that these teams will work only one after another.

If you will assign this crew in one team and trucks in other teams then it will model the real case. "Remaining crew" usually includes excavators that determine productivity of assigned resources. Team-Lag

Rafael Davila
User offline. Last seen 11 hours 9 min ago. Offline
Joined: 1 Mar 2004
Posts: 5169

After resource leveling the following does not make sense to me, what I am missing?

2022-07-01-19-45-34-Activity-Gantt-Lag-Calendar-3-Lag-Calendar

This functionaliy was created as the response to the request from one of our customers.

They asked if it is possible to model following situation:

Certain amount of trucks is required for the first part of the earthworks but when the distance increase the number of assigned trucks must increase also. So trucks must be added during activity execution depending on the distance from the initial point.

Additional trucks are assigned as the new independent teams that can start to work with the volume lags from activity start.

Yes, this is minimal lag because trucks can be unavailable at the moment when their assignment is possible.

Rafael Davila
User offline. Last seen 11 hours 9 min ago. Offline
Joined: 1 Mar 2004
Posts: 5169

NICE! I even increased the resource loading and leveling difficulty and still works as expected, it looks like it is not a hard or fixed lag but a minimal lag and this I like.

teams-lag-30jun2022

Rafael,

please download new version where this bug was removed.

Thank you!

Vladimir

Rafael Davila
User offline. Last seen 11 hours 9 min ago. Offline
Joined: 1 Mar 2004
Posts: 5169

Other activities that are resource loaded are not shown, please follow the link.

https://www.mediafire.com/file/115gyfs2vvmtsc8/Lag-Calendar.002.sprj/file

Best Regards, Rafael

Rafael,

I could not repeat your case. I created the same project and the lag was not broken.

Please download the latest version and check if the problem still exists.

Best Regards,

Vladimir