theory • knowledge management in construction
Many of the methods mentioned are product oriented, in the sense that the ES’s activity is dedicated mainly to the knowledge base, and to some extent to the inference engine and user interface. 2.2 Expert Systems for construction planning In the construction sector the overall project performance is strongly dependent on the project management activity. In this regard, process planning is well-known to play a crucial role and, despite the long-lasting efforts, most of the related issues still need to be fully addressed. In fact, project control and monitoring is based on a specific project plan determined considering beforehand numerous constraints such as resource availability, completion deadlines for tasks and budget limitations. Cost increases or delays can easily result from poor estimates, schedules or decisions related to tasks decomposition and choice of construction technologies. The planner, in turn, generally identifies constraints, evaluates interactions and solves the related conflicts on the base of the experience he acquired from previous projects. In this context, few process planning aids exists, and the available tools are rather analysis tool of existing plans than tools for plan formation. The main reason of the inadequacy of planning tools in addressing this multi-variable problem (resources, tasks, technologies, budget, schedule, etc) is due to the programming methodology used in developing the tools themselves. Algorithmic or procedural programming implemented in commercial construction and project management solutions cannot, in fact, conveniently represent, formalize or leverage acquired expertise. Moreover, they don’t provide for an integrated process planning environment, vanishing the full potential of other computer-aided systems such as CAD for design or CAM for manufacturing. Integrated tools for comprehensive process planning could allow since the design stage considerations related to manufacturability or constructability, fostering the achievement of better products. Therefore, even nowadays, despite the huge steps moved forward in terms of available technologies and computational capabilities, is still possible to refer to the issues raised decades ago from (Zozaya-Gorostiza, 1989), to briefly summarize the main motivations for developing computer tools for process planning in construction: • process planning is crucial in design and project management; • process planning is a difficult, knowledge-intensive, challenging process; • there are virtually no integrated computer tools that assist during the complete process planning and project management cycle; and • there are similarities in process planning across different domains.
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