Flowsheet development is a series of steps in which a conceptual process is iteratively evaluated, modified, and reevaluated until it becomes practical. Although it can take many forms (for instance, the plant can be built and then modified), it usually follows a pattern of laboratory work (which may be multiphase), piloting (which can also be multiphase), and demonstration piloting in cases when commercialization risks are particularly high.

A process needs to be guided toward an operable, low-cost flowsheet that will produce a salable product, while avoiding tangents that are not economically effective even if they are technically effective. The process can be based on a sound development program, or on information from prior operations. Process development is normally undertaken in conjunction with engineering and economic studies (scoping, prefeasibility, feasibility, etc.) that are often performed by an engineering company. Hazen can provide a preliminary process design and preliminary capital and operating cost estimates to the engineering company or to the owner.