The document discusses using cluster analysis to identify outliers in time series data. Cluster analysis involves grouping similar data points together. It can be used to spot abnormal patterns and outliers in industrial time series data, which is important for tasks like fraud detection, asset health monitoring, and detecting non-technical losses in networks. The presentation provides an example of using Predix Analytics on a non-technical loss detection project, where cluster analysis was used to identify outlier data in time series signals from networks.