Mohd,
Keep two schedules:
- One with the committed dates and for the record send letters to your suppliers and subcontractors instructing them to keep on schedule.
- The second with the expected delays so you can make crucial decisions as to control costs with the knowledge these delays might happen. This schedule will provide you for alternate plans as the job progress and at some time it might be you have to disclose it as your revised plan with some strategies as to reduce the impact of your delays, release it at the right moment, not before.
The management of your company is correct, if latter the Owner delays the job and you reported these delays then concurrency will happen and you will not be able to claim for delay. It might happen that the Owner claims he is pacing, and will not even grant EOT. Yes same as contractor pacing there can be owner pacing.
By the same token if the Owner knows he will be delaying the job due to a change he is to issue, he will not tell you in advance so you re-schedule the job and get delay reimbursements. Just do the same, don't play the "fool".
What if eventually they can deliver and expected delay never happens?
If the delays do happen you will always be able to say that you tried your best and even asked your suppliers and subcontractors to keep on schedule, that you never recognized a new baseline based on deliveries that break their commitment, that you have your commitment to the Owner and this is not negotiable. Then you show the Owner the letters you sent your subcontractors and suppliers asking them to keep on schedule.
And who said the use of the schedule as a claim tool is not in opposition to the best use of the tool as a management tool? B.S. !!!!
If you are using lag to represent deliveries of your procurements you shall re-consider in the future using activities to represent the deliveries, these are easy to maintain either using expected finish constraint or a formulae or global change to keep finish date aligned with expected delivery date. It helps to see float and criticality, it helps you control calendar of the delivery activity, usually in calendar days while predecessor and successor in different work days calendar, something some scheduling software cannot handle. Even helps with the start of the delivery, usually a release document and not an automatic start as in the case of lag.
Best regards,
Rafael