ATS Manpower Planning in Practice: Introduction to a Qualitative and Quantitative Staffing Methodology. This document details the tactical perspective of the manpower staffing methodology in Air Traffic Service (ATS) organisations. It intends to give Manpower Planners (MPs), supervisors, controllers, senior management and staff members at all levels, detailed considerations on the day-to-day know-how of MP work. It clarifies qualitative and quantitative aspects of the staffing methodology in ATS organisations. By focusing on the day-to-day way of determining the number of controllers needed to perform the core task of an ATS organisation, this document may also foster the common understanding of broader and long-term MP considerations in the manning process. The ways of constructing a roster and improving it are also described. The advantages of shift scheduling software and their limitations are presented.