This study uses the two strands model of Soft Systems Methodology (SSM) with other change methodologies within a single intervention to elicit new insights into a multi-methodology and address problems detected in a women's prison in Turkey. Evaluating the strengths and weaknesses of SSM, the study proposes to use SSM, as a core approach, with Strategic Assumption Surfacing and Testing (SAST), Critical Systems Heuristics (CSH) and Interactive Planning (IP), as subordinate methodologies. The multi-methodology integrates group formation of SAST into the cultural and logic-based streams of analysis of SSM. Also, it adapts assumption surfacing, dialectical debate and synthesis of SAST, boundary questions of CSH and resource planning of IP to a logicdriven stream of inquiry of SSM. The study reports the methodological effects of this approach and examples of psychosocial services and a performance appraisal system to assist human well-being and promote public safety in a women's prison.