Case-based reasoning (CBR) has emerged as promising technology for decision support. However, its application to large scale industrial problems has been negligible. We believe that the lack of usable problem-solving cases is the major factor limiting the wide spread use of CBR in complex industrial environment. We propose a framework of methodologies called case base engineering (CBE) that can be used for the development of high quality case bases. The framework is presented in light of our CBE experience in application to plastics extrusion facility and aircraft maintenance. Finally, we identify issues for future research.