The issues of waste generation in batch process plants differ in many aspects from those in continuous plants. Despite the smaller-scale of processing, complexities from discontinuities and run-to-run variations make waste minimization in batch plants more challenging. In this paper, we introduce an integrated qualitative-quantitative methodology and decision support system, called Batch-ENVOPExpert, for assessing waste minimization opportunities in batch processes. First, a qualitative analysis is performed to identify the sources of wastes and to derive recipe-level waste minimization solution. This is followed by detailed analysis at process variables level using mathematical simulation. The application of the methdology is illustrated using a propylene glycol case study. © 2005 Elsevier B.V. All rights reserved.