Computer-aided design, analysis and/or operation of chemical products and processes that manufacture them require a number of computational tools. As these tools may come from different sources and disciplines, an important issue is how they can be used simultaneously and efficiently for the design, analysis and/or simulation of a specific process-product? One alternative is to employ CAPE-OPEN standard interfaces for integration of the set of diverse computational tools that may be needed to solve the problem. The objective of this paper is to highlight, through examples, the integration of different computational tools according to problem specific work-flows/data-flows. The reliability of the integration of different tools is illustrated through two case studies. In case study 1, the tools Simulis(R) Thermodynamics (PME) and ICAS-MoT (PMC) are combined for the calculation of thermodynamic properties through the use of a standard middleware (DLL file). In case study 2, the interoperability between ProSimPlus simulator (PME) and ICAS-MoT (PMC) is highlighted for simulation of a new unit operation and combined with other unit operations that can be found in the host simulator. A ProSimPlus-ICAS-MoT-COFE interoperability is also carried out successfully to proof the interoperability of the different computational entities. Furthermore, the introduction of the multiscale modelling concept and its application through the CAPE-OPEN standards is highlighted. (C) 2008 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.