For some authors this research method is an integrated system and offers the opportunity for a holistic view that combine data collection methods such as archival searches, interviews, questionnaires, and observation. Literature review The literature review shows that the case study research method is an integrated system and combine archival searches, interviews, questionnaires, and observation (Eisenhardt, 1989). Additionally, Yin (2017) declare that the case study method has variations including single or multiple cases, can be limited to quantitative evidence or can be part of a mixed -methods study. From different authors other parameters were studied: strategy description used to explore and test the theories (Cesar et al, 2010); research question typology (Godoy, 2006); case study type (Harrison, Birks, Franklin, & Mills, 2017); representativeness of the objective of the work (Stewart, 2014); data collection sources (Ajayi, 2017); existence of data triangulation (Heale & Forbes, 2013); explanation of the procedures (Bhakar & Sikarwar, 2014); analysis of psychometric indicators (Hair, Black, Babin, Anderson, & Tatham, 2009); explanation of the analyses performed (Heale & Twycross, 2015); comparison with previous studies (Labani, Wadhwa, & Asthana, 2017); suggestions for future studies (Inayatullah, 2013).