Non-engineer appraiser valuing four expoxy resin related plants in four states - Houston based - return on investment based on volume of product produced, less costs to produce. Replacement costs new must be obtained less depreciation including physical, functional and economic. values used mostly for tax consulting, insurance and some lending purposes. Most lenders utilize an audit by a major accounting firm. Replacement values are part of the assets and maintenance and depreciation costs are part of the costs to produce. I have been asked by a lender to value assets and certain leasehold agreements, etc. They do not want a value based on the income produced, however, volume and quality have a distinct effect on economic as well as functional depreciation.  In short, I do not have a specific methodology available, however, one can be established based on either sound appraisal methodology or principle accounting practices. please contact us for any information that we can provide you.