This thesis presents a process model for design composition using an abstraction of form and function characteristics of design solutions. The design process model is based on adapting previous solutions to generate new designs using derivational analogy. The model relies on a geometric representation of design compositions. This representation encodes functional and form attributes of design and is used to build compositional characteristics of the design. The research uses Solution Traces (Sol-Traces) as constructs for recording and reusing the design composition. The trace consists of compositional steps. The trace – the sequence of steps - can be replayed to generate design solutions.
Design reasoning with architectural cases has a long history in architecture.

Generative case based reasoning using derivational analogy is a powerful problem solving technique that enables new designs to be created by utilizing the generative path of prior designs. This technique is adapted for use in developing a design assistance system for design composition in architecture. Solution Traces (Sol- Traces) are used within a CBR methodology for a design composition assistant: the TRACE system. Cases in TRACE include architectural representations such as floor plans, form diagram, function diagram, and the sequence of design composition steps that lead to a particular solution. The TRACE system utilizes two strategies, transformations and formative ideas, to generate forms. Cases and their components are classified and indexed in the case base using both form and function attributes. The thesis presents three worked examples using the TRACE system.

The main contributions of the research are: the abstraction language for design composition using the Sol-Traces representation and the process model for design composition using this approach. Another contribution of the research is the application of the generative CBR, using derivational analogy, in architectural design composition at the early phases. The research also provides the development of the TRACE system as a CBR system utilizing the research findings.