  Non-Markovian effects are ubiquitous in physical quantum systems and remain a
significant challenge to achieving high-quality control and reliable quantum
computation, but due to their inherent complexity, are rarely characterized.
Past approaches to quantifying non-Markovianity have concentrated on small,
simple systems, and we show that such measures can capture properties that are
irrelevant to applications. With this insight, we propose a method for
constructing relevant quantifiers of non-Markovian dynamics and illustrate the
scheme's computability by characterizing a model quantum dot array.
