Decision making processes and systems to support the same have focused for the most part on narrow disciplines, paradigms, perspectives, and pre-determined processes. Apart from these most decision processes and systems are designed to solve simple problems and are therefore unable to support complex problems that consist of interrelated decisions that span multiple domains, paradigms, and/or perspectives.To address these problems we propose conceptual decision-making and modelling processes. A flexible object-oriented decision system framework and architecture was developed and implemented to support the proposed processes. Some of the key concepts that we have been able to explore and implement are generic modelling ideas, such as data-model, model-solver, model-model, solver-visualisation, and data-visualisation independences. Specifically we have been able to explore the integration of models of different types, levels of complexity, depths of integration (aggregation, pipelining, and splicing) and orientations (satisficing as well as optimising).