Calendars - What are they for?

Hi Mike,



Would you mind to elaborate what are the differences between a "Construction Programme" and a "Contract Programme"? Is your "Bottom-Up" planning applicable to both?



I believe that you always emphazise the practice of "bottom-up" technique, and in the case of multiple time zones and locations, I supposed that your calendars are well defined before pressing F9 (for some softwares)? Will you share with us how you do it?



Best regards

Vlad & Mike,



I thought you were good influence for us who are juniors?



Again let me try, I believe that changes to "Calendars" or time periods or working hours certainly affect "original durations"; resources and maybe project completion or other contractual milestones.



So how can you say that I can make any changes I want (only to calendars and working hours)? Do you mean without any reference to the contract?



I’m not a contracts man, so I don’t know of any contract that specifies the use of calendars (for a schedule or program).



Again for example: Say you got an EPC project to be built in UAE, the design to be done in Europe, your QS is done in USA, and your procurement department is in Russia, is a compromise regarding calendars and working hours not required or not necessary?

Hi Anoon,

Baseline or contractual schedule set targets.

Changes of woking hours mean corrective actions in the current schedule, not in the baseline. You may decide to work 10 hours per day because you are behind the baseline schedule. It does not mean contract change.

Dear All,



I really need some clarification here... Would you agree that changing "calendars" will certainly affect the "original duration(s)"? I’m talking from an approved "baseline schedule" taking into consideration that calendars were discussed, agreed and approved beforehand.



Can you call a change in calendar, a contract variation or a change order? Or it is only a choice or discretion of the contractor considering his/her resources and the corresponding risks?



Mike, please consider that all things are fair and transparent all the time (no strategies, betrayal, etc.)

Thanks Mike -That certainly seems simpler than my way.



Correct assumption that there won’t be by-passes.



Excellent point about time lag of rain to increased flow! I shall have to investigate that one.



Is there anything wrong with the TRA / resource approach I described, do you think? My only hesitation with your calendar method is that the earliest date for shutdown assuming dry weather wouldn’t necessarily be indicated on the schedule (if it happened to fall on a randomised calendar rain day)?



Thanks again,



Gary

Mike / Vladimir / others:

I’d appreciate your advice on the following:



Currently working on a UK sewage treatment upgrade job which requires a number of partial process shutdowns (1-8hrs each)



As flow through the works is significantly increased when it rains, these shutdowns will only be permitted during dry weather. So the weather will affect the the date of the work but not the duration.



It rains every month in the UK, but some months are wetter than others.



I was thinking of using historical weather patterns to estimate a Time Risk Allowance sufficent to give say 95% confidence in at least 1 dry day, and adding that as only sucessor to the shutdown activities. I could then assign a resource to the TRA with different max utilisation for each month to represent the changing likelihood of wet days in that month.



Does this sound like a reasonable approach? Would I be better off using calendars?



Many thanks,



Gary

Mike & All,



Really new in planning and have this question.



1) I was advised to put a no holidays and non-working days calendar for the contract milestones, why?



2) We are using FIDIC, and the signed contract does not specify working hours and regular holiday (Sunday). The programme was built on a 8 hour a day and 6 days a week. Is there any implications to this?



Regards,

Mike,



This is your thread, I’m just trying stir it to get the desired taste (hope you won’t mind).



Another question that comes to mind is that: Supposing that you had set your calendar(s) and working hours in your baseline schedule and it was approved, and during actual implementation of your schedule or program, is it proper or allowed to change "calendar(s)" and or working hours? Please note, only calendars and/or working hours will be changed, no changes in sequencing or logic, duration, and or all others to remain as in baseline.



cheers!

In the normal building construction we use separate calendars for 1st and 2nd shifts, for mechanisms, for curing. Concrete is supplied 6 days per week - so concreting has its own calendar.

Weather factors are used in risk analysis - there are optimistic, most probable and pessimistic calendars for activities and resources.

Best Regards,

Vladimir

Well Mike,



With the wide variety of project types and surroundings, this topic is hitting the nail on its head and making clear that no project can go with out a good set of calendars.



Glad to be able to share my experience with all of you.

Hi Mike,



Let me get back to you on your statement:



’’I usually have 2:



1. Outside Working with weather days.

2. Inside working with no weather.``



This of course depends completely on the type of work. I’ve been doing a rail road project a while back and with 8 tracks being re-routed while they were all in use, we had different working hours per track. Meaning that during the day time 6 tracks were being used while there were only two we could use/modify during the day time.



With new routes for all of them, every once in a while we have all 8 tracks for just 48 hours available and that meant a tremendous amount of work to make sure that after the weekend the tracks were all (at least 6 of them) available again for train traffic.



We could not have managed this project with (what I still think was the minimum) of 12 calendars. Move would have been useful, but would also complicate things more planning wise.

Hi Mike,



You can call me "doubting Thomas", but to be honest, I just don’t want an answer that sound like it came from a software sales rep. It’s about 1:45 am now in my place and I’m not working for a "call center" or something, it is that, I just cannot sleep thinking that "Calendars" (plus working hours) really is a big issue when it comes to scheduling and I believe that for now, nobody really is so concerned that can or may give a reasonable explanation or calculations considering the use of multiple calendars and working hours and its effect to work productivity.



And I don’t want to end up by just setting a default calendar.



Best regards

Hi Mike,



How many days you work in a week (productive days)?



I have a question regarding combination of calendars and its effect to the overall scheduling (regardless of the software used).



For example:



You got a project in one place and you need resources and supports from anywhere (globally), which means different holidays, weather conditions, working hours, etc. etc., some holidays may fall on Saturdays and Sundays and others on Thursdays and Fridays, which leaves you with Monday, Tuesday and Wednesday (with 100% productivity), but still you’ll be having problems with the "working hours".



Now if you use several types of calendars to suit each and every requirement (considering different places and factors) , can you expect to get work productivity equivalent to say, 6 Days a week, 8 hours a day (from the assigned resources)?



What if you just use 24/7 (without any holiday) calendar?



Any comment is highly regarded.



Cheers!

All very well talking about adding weather days etc, but in the current market we are losing out at tender stage to companies who recklessly submit programmes that are clearly unachievable. Given the quality of some planners I have worked with, I would suggest it is inexperienced staff who are putting their companies at risk, rather than "strategic commercial" decisions being taken. Prudent companies are then forced to play the same silly game just to win work, and the programme periods are driven ever shorter.



If I were to start adding days for down time and inclement weather, our estimating department may as well pack up and go home now, as we would never win any work.

I’m using some calendars for defining workable periods in fieldwork combined with breeding seasons. This way I don’t have to make sure my tasks are linked to milestones defining the start and end of a breeding season.

Dear Sirs,



I think so, the P3 software is not designed for the time period worked per day if the planning unit is "day".I dont know whether it is taking 8hrs/day or 10 hrs/day or 24 hrs/day...... But i came to know it is taking 8hrs/day as default........P6 is ok for this issue...



Awaiting for your experienced replies...





Regards,



S.Shaji Mohamed...

Mike R,



It’s a wild guess. 2-3 days a month of the wet season are made non-working days. The contractor defined the assumption in the narrative.



Thanks Neil, it’s very reasonable.



Cheers,

Nestor

Nestor,



I’d suggest that you could take account of it and reduce the EOT entitlement, but only if you could soundly demonstrate that the anticipated weather had not occured or the contractor had not had to utilise it for another non-excuseable delay (i.e. the contractor has a right to the float that he has built into his programme).

How do you go about setting up calendars for weather days in the future? I once experimented with adding the forecast weather days ahead of time to a schedule calendar. All it did was to create a lot of questions from people looking at milestone dates.



My weather day procedure is one activity at the end of a project that gets reduced/statused as actual weather days occur. A narrative or TIA (Time Impact Analysis) explains the delay.



I guess you could add the calendar non work days after the rainy day but by then the activities are statused and the calendar does not drive them.



Mike

Hi Mike,



One interesting issue on calendar is, say a schedule uses calendar with allowance for inclement weather and holidays. However during the construction period the there were fewer inclement weather than predicted. The contractor even worked during Sundays and holidays on critical activities.



Would you allow the contractor to use the schedule to assess EOT without altering the calendar?



Cheers,

Nestor

Mike



That’s one of the reasons we are using calendars.



I remember that due to a flood desaster some years ago some hundred of projects (repair, maintenance, revamp) had to be stopped for some weeks. I needed less than half a day to bring planning into line with this situation using calendars’ non working time.

In this case not all activities had to be interrupted.



Flexible use of calendars for me is one essential of a planning software.



Regards



Dieter