  Current systems design optimisation methodologies are one-sided, as these
ignore the socio-technical integration between stakeholder preferences ('what a
human wants') and the capability of technical assets ('what a system can
deliver'). Moreover, classical multi-objective optimisation methods contain
fundamental mathematical flaws. Also, the often-used classical Pareto front
does not provide a single best-fit design configuration, but rather a set of
design alternatives. This leaves designers without a unique solution to their
problems. Finally, current multi-objective optimisation processes are not well
aligned with design practices, because they do not sufficiently involve
decision makers and do not translate their interests into a single common
preference domain to find an overall group optimum. This paper introduces a new
Open Design Systems (Odesys) methodology and a new Integrative Maximisation of
Aggregated Preferences (IMAP) method, implemented in the Preferendus tool. Its
added value and use are exemplified in two infrastructure design applications,
which show how to achieve the pure best-fit for common-purpose design results.
