If claim for extension of time is approved by Engineers/Project Management/Client, what should project manager take next step for his company?

a change of time or extension of the time of the project means simply that the whole plan will be hindered including the critical bath or time plan or productivity schedules or human or equipments used efficiency that the project manager should take things lighted he should review every things that contributed to the extension of time , before he approve it he should justify clearly why is extension is needed and how does that reflect on the cost and expenses and he should take the matter serious and give prompt time for complete execution of the project and report all to the senior management and claim their approval as well   

Thank you for the invitation . I agree with the engineer Walid Alnuaimy 

Thanks for invitation -

       Here he must go back to the contract for therequired details and then take the appropriate  *decision

He should go throgh the terms and condition mentioned in the contract document, regarding extension of time of completion. Accordingly he can only approve the time of extension.

Thanks for invitation,

Make a change request and revalidate the project schedule, revise the project plan with time, cost , delivery etc. Inform one and all.

extention of time also means higher cost ...

Who is paying for this?

Is there enough funding there to pay personnel and equipment rental?

What is the new timetable and delivery/completion date?

What is the additonal cost? 

I assume from your question that you mean the Contractor's Project Manager. In such case and according to FIDIC, after the approval of extension of time by the Employer (client), then the Contractor should update/modify the work plans within7 days. Also, in case there is an additional cost involved as a result of the extension of time (at no fault of the Contractor), then a notice and a claim should be submitted to the Engineer/PM/Employer for the additional cost. Please note that other types of contracts may have different conditions, so it is important to specify the type of contract and apply its conditions.

Thanks for good invitation ,

Solve the problems that caused delays, quickly + agree with experts opinions

Any extension of project time means a delay for the whole project, consequently project cost.

PM should review terms and conditions to check for penalties because of that delay, then maybe he/she should review all remaining project milestones to see if execution time can be shrunk to avoid any penalties due to project delay.