This paper aims to improve MB Manufacturing LLC’s Maintenance Department System by establishing a Weekly Preventive Maintenance Standard Operating Procedure. As the record shows in Breakdown Maintenance Report in 2021, MB Manufacturing LLC has a loss of approximately 297 Production hours/ USD198,801 In this paper, the researcher uses various tools such as McKinsey’s 7’s, Decision Analysis using Kepner-Tregoe Approach, Why-Why Diagram, and How-How Diagram to identify the root cause of the problem and propose a System Design for the Maintenance Department Standard Operating Procedure. As a result, the researcher has been able to provide the Maintenance Department with the steps for the Solution Planning and Implementation as well as with Failure Mode and Effects Analysis the team should be more focused on improving process controls or re-engineering the process step, shall there be any new issue arises.