It is expected for the ISO/IEC/IEEE 29119 to have a favorable impact on this software testing domain. However, in small businesses in Lima, these activities are performed in uncontrolled way, tests do not achieve adequate coverage and the software operates with errors. In this study an exploratory research was performed in organizations conducting software testing, the objective was to determine environment factors to affect the extent of adoption of software testing practices. The analysis was performed using a multiple case study analysis of four units, considering two types of organizations. Organizations that acted as software factories under a contractual scheme presented a higher level of adherence to standard practices than those who acted as part of a software development team. In addition, the External Pressure factor is one of positive influence for the first group and negatively for the second group.