Purpose: Nowadays Retailers are dealing with not only their rivals' competitions but also pressures of customers' demands, shorter product life cycles, and especially the acceleration of innovation in technology. To survive and develop, Retailers continue improving their performance through Business Process Management (BPM), which has become an essential instrument to enable their business strategies and objectives to be well-controlled and fulfilled. This paper aims to propose a format of Standard Operating Procedure (SOP) to implement BPM effectively with a task-based approach for operations activities including Merchandising, Operations, Promotion, Controlling, Personnel, Supports, and Supply-chain in retail. Design/methodology/approach: To achieve the objectives, Descriptive method was used, comprising (i) Survey approach (interview and questionnaire) to examine the frequency, attitudes, beliefs, prejudices, preferences, and opinions on how BPM was implemented with the SOP approach of interviewees, who were key persons in big retailers; and (ii) Observational approach to view performance of retailers in the business environment (real-life situation instead of laboratory) and crosscheck the result of survey. With the research results, the author may identify all most key tasks in a Retailer, which are prerequisites to establish the full set of SOPs so that BPM will be implemented efficiently. Findings: Different from previous research, this paper focuses on how SOP contributes to BPM implementation in the retail industry as well as illustrates that besides initiative process modeling, identification of key tasks in an SOP is very essential to make it clear and comprehensible for operators to follow. Although RACI/RASCI matrix 1 (Petrakova and Reusch) is used quite popularly in many organizations, it does not satisfy all requirements of Retailers to implement BPM and deploy SOP. Therefore, the proposed "TRATS" model (Task, Responsible, Approval, Time, and Standards), which are based on basic tasks in retailing, presented in task-based SOPs, may cover almost the gaps and help Retailers perform BPM more efficiently and effectively. 1 RA(S)CI stands for Responsible, Accountable, (Support), Consulting and Informed. 2 Research/practical implications: Through the research, author would like to emphasize that BMP and SOPs are well-performed only if they were easily comprehended and firmly conceived by employees, so that business objectives may be accomplished; therefore, SOPs must be detailed and comprised all operational aspects for employees to comply with. The research is also the combination of academic knowledge and practical experience of BPM implementation in terms of SOP, of which expectation becomes a reliable source and basic reference for further research in BPM as well as a guideline for Retailers to improve operations management. Originality/value: Differing from manufacturers, retailers are about people while technology cannot completely replace human skills; therefore, BPM may be presented as items of works chronologically in written, so-called "task-based SOPs", which are more comprehensible for employees to perform and accomplish the objectives of enterprises easily and efficiently. Expectedly, SOP with "TRATS" model may be useful for practitioners because it can cover almost all important aspects in BPM implementation, therefore it can help them to improve their business performance. For academics, "TRATS"-SOP (or task-based SOP") approach may be a new point for researchers who are interested in BPM of the retail industry and want to develop it in further literature.