Analysis of the sequence of arriving aircraft, as well as identification of the cases of spacing violations, is an important step in evaluating performance of the Terminal Maneuvering Area (TMA) Air Navigation Services: without knowing the current performance levels, it is difficult to identify which areas could be improved. This work presents an enhanced data-driven methodology for evaluation of arrival aircraft sequencing and spacing inside TMA, inspired by the previous research presented by EUROCONTROL EEC [1]. On several use-case examples using historical dataset from Stokholm Arlanda airport, we illustrate how to effectively capture different aspects of flight inefficiency, as well as characterize and quantify sequencing effort and aircraft spacing. This is a contribution towards the development of the adaptive multidimensional key performance indicators (KPIs) tailored to the specific aspects of airspace performance, and designed to serve further airspace optimization initiatives.