The design of industrial processes that use physical, chemical, or biochemical transformations for the production of useful products. It is used for the design of new processes, plant modifications, and revamps. It starts with conceptual and feasibility studies, and includes detailed material and energy balances, the production of block flow diagrams (BFDs), process flow diagrams (PFDs), engineering line diagrams (ELDs), and piping and instrumentation diagrams (P&IDs). It also includes the production of reports and documents for plant construction, commissioning, start-up, operation, and shut-down. The reports and documents are used by vendors, regulatory bodies, operators, and other engineering disciplines.