هل المهندس من واجباته التنفيذ فقط للمخططات الخاصة بالمشاريع ام يجب عليه ان يعدل عليها ويجعل التصميم الاساسي اقل تكلفة كنوعاً من الابتكار ؟

Yes, the Engineer must make the implementation less costly material and time to serve the interests of the parties to work after their approval

نعم يجب على المندس الاجتهاد في مجاله كاابتكار طرق تجعل التصميم اقل تكلة و اكثر احترافية و تطورا 

Study and review the drawings before starting to implement and can modify the Omrasla designed to be studied --- and his attempt to have the best and cheapest ways to implement high quality

It is implied in the question that we are talking about a construction engineer who works for the contractor - the executive party. As long as the engineer abides by the specifications and drawings that are part of the contractual documents, it is absolutely valid and commended to find less costly solutions. This is considered efficiency and the profit of the contractor should increase especially if the contract is  lump sum. However, he should be careful not to change any requirement or specification or detail that is required by the contract and his solutions should be efficient time-wise. Since he is an engineer and not a foremen, he can be critical and propose alternatives or variations to the consultant in some certain situations. But unless he receives an official approval he cannot change any predetermined requirement. 

being an engineer we should follow the project specification. if there is better solution then old design and it is fimiliar with project specification and regulation then only we can propose or amend alternative solution.   

Of course, the engineer must look at the design with the engineer's eye. Perhaps it was a wonderful design that he took and executed, and it may have some flaws. He must review his superior before the amendment. If the amendment is approved, modify that design to another that suits the quality and cost standards.

المنوط بة عملة فقط  وفى حالة وجود اى تعديل او ابتكار ييد المشروع فعلية ابلاغ الجهة المنوط بها ذلك مع الشرح واخذ الموافقة منهم

يمكن للمهندس رفع توصياته ومقترحاته للمالك أوالإستشاري بإجراء تعديلات بما فيه مصلحة العمل والمالك

نعم اذا كانت الفكرة جيدة واقتصادي توثر بشكا ايجابي على مشروع

يجب على المهندس الالتزام بتنفيذ النطاق وتنفيذ خطة ادارة المشروع والبرامج بدقة اما عند التنفيذ وقد وجد ما يتطلب احداث تغيير لصالح العمل فعلية ان يتبع السياق لاحداث هذا التغيير بعد استحصال موافقة جميع الاطراف المعنية .