When planning a well intervention, there are many factors that need to be taken into consideration prior to the execution of the operation. Designed guidelines are critical to the success of the milling operations in terms of saving rig time and successful downhole milling operations. These guidelines should include a structured pre-job information questionnaire, provide a more accurate picture of the problem, and also allow for a more detailed and auditable fit-for-purpose solution to the problem in terms of equipment selection, job procedures, and well programming. However without a set of stringent guidelines to assist in detailing the correct tools required for each application, the success of each intervention may not be realized. Through case histories this paper will show that utilizing structured guidelines, appropriate technology and tool designs lead to successful through-tubing intervention milling operations in cases when removing multiple composite bridge plugs. Discussion will involve the pertinent information required prior to equipment selection and job engineering and how that information relates to the equipment’s performance and overall success or failure of the objectives of the intervention.