The key to any revamp project must be an objective look at the condition of the existing plant. The findings must be documented and organized in such a way that they cannot be refuted and can be readily accessed by the project team and others throughout the project.
Conducting a thorough assessment is a subject in itself and only the high points can be discussed here. The assessment must be organized and in sufficient detail that parts of it can be pulled out and studied separately. This is to determine what technology needs updating, or really isn't working correctly, so as to arrive at specific replacement sequencing.
The assessment should also take account of conflicting points of view and try to resolve those issues. What any assessor will often find is that key data, for instance on equipment, is missing, misleading, contradictory or confusing. Moreover, since the technology of a revamp project is typically 20 to 30 years old, other newer technologies have come to the fore not previously available at the time the plant was built and must now be considered. These options must be studied with a view to taking advantage of capacity increases or process improvements if feasible.
The leader of this effort must not only present alternative strategies, list the relative merits of each and then make a final recommendation but be prepared to defend that position. The assessment will continually be challenged by plant managers intent on saving money, by technologists who cannot believe that the equipment is really in such poor (or good) condition, and by people new to the project who have not looked at all the data. These projects are usually cost-sensitive so there will be all manner of challenges to the assessment. Continuous questions such as: has Option A been considered or what about this Option etc. However, the more of these issues that the assessment can address, the more readily can the scope be defined.
A good source of information is a review of the plant's history. For example: the design life of a plant may be 20 – 30 years and the plant being assessed is in the same range. If there has not been a lot of capital put into it, especially projects addressing infrastructure, then you will be in for a very challenging project! If, however, the plant is well past its useful life, then revamping will make little sense at all.