Software outsourcing partnership (SOP) is a type of client-vendor cooperative relationship for achieving mutually beneficial goals and is totally based on mutual trust and commitment. Usually a fruitful outsourcing association may possibly convert to outsourcing partnership. The development of SOP depends on the employment of various factors like 'mutual interdependence and shared values', 'organizational proximity', 'mutual trust', 'effective and timely communication' and 'quality production'. The objective of the research is to find out practices through Systematic literature review (SLR). These practices will be used to implement critical factors in SOP. We have identified a list of 142 'practices' for 14 critical factors through SLR methods. This paper presents preliminary frequency analysis on practices in SOP. We have distributed studies found on publication venue, organization size, collaboration model used, study quality and year. Further, we have listed top venues and authors. The results might benefit the researcher interested in knowing about who involved in outsourcing partnership. Our outcomes can help practitioners working on outsourcing collaboration in the software development industry. They can determine from the results of the study where to outsource and which are the emerging countries in software outsourcing.