HEA is a licensee of PDQ$®, a proprietary computerized service for obtaining preliminary mechanical designs and estimates of the cost of individual items of chemical process equipment, which are of vendor quotation quality. PDQ$® data are updated quarterly by the licensor, PDQS Inc, Gates Mills, Ohio, so that estimates represent current prices. This system is widely used throughout the chemical and refining industries. Estimates obtained using this system can be used as stand-alone prices for single major equipment items, or as the basis for installed costs of process plants which may be composed of many items of major equipment.

HEA can provide cost estimates for complete process plants, with or without associated offsite facilities, by any of the industry standard estimating methods, from the simplest (and least expensive) to the most complex (and costly). Often the installed cost factor method, which is intermediate both in accuracy and in cost of preparation, meets clients' needs. This method is well founded theoretically and in practice and has been in use for many years in petroleum and chemical process plant cost estimating. The method relies on the observation that the total installed cost of major equipment items can be reliably represented as a multiple of the equipment cost. (The equipment costs themselves can be estimated using PDQ$®.) For a given type of equipment and process, the multiple, called the installed cost factor can vary depending on of the size of the equipment item(s), specific process design details, site location, and other factors. It is in identifying which of these factors is important, and evaluating its effect, that the experience of HEA's professional estimators is of critical importance.

Typically, a capital cost estimate includes a contingency allowance, separately estimated and itemized. The term contingency allowance, well established in the profession, at times is misleading because it implies the probability that these funds may not be spent. Funds represented by the contingency allowance are included to cover the many small items not estimated individually or covered in detail elsewhere in the estimate, such as variances in labor quantities or bulk material costs. This allowance represents funds which are expected to be spent, and which therefore properly are to be included in the estimate. The contingency fund is not intended to cover additions to the scope of work.