Recent advances in flowsheeting simulation, particularly with respect to new and improved graphical user interfaces coupled with fully interactive flowsheeting calculations, have made possible a further step forward in easing the job of the process engineer. By developing an “Engineering Toolkit” for use in conjunction with a flowsheet simulator, engineers can now perform the front-end or detailed process design of equipment while enjoying full electronic transfer of the required data. As far as the user is aware, process simulation and process design are integrated into a single environment. The user interface to either flowsheet simulation or engineering design is the same, namely a PFD representation. Changing from simulation to design is accomplished by a simple menu selection. Simulation data is stored in a database which is also directly accessible by the design programs. Specific engineering design calculations are chosen from a list. The list presented has relevance only to the object selected from the PFD, normally either a unit operation or a stream. Much of the data required for front-end design work comes from a flowsheet simulator. The engineer has direct access to these data but is presented only with the data of relevance to the particular engineering calculation and simulation object selected. The data may be changed prior to the design being performed. Typical design calculations performed by the Engineering Toolkit are control and relief valve sizing, tray sizing, vessel design, separator sizing, pump selection, etc. This paper describes the “Engineering Toolkit” concept in some detail and presents powerful arguments in favour of this general kind of system design as a means of integrating the tasks of process engineering in the future.