OpenEIS will be released as open source software and is envisioned to be a flexible platform that will support multiple applications developed by the National Laboratories and third parties for evaluating building energy and operational performance of building systems based on data sets uploaded by 'users" of the software. The initial use case for this platform is commercial buildings analysis and diagnostics. The data sources are expected to be portable data loggers, building automation systems data log files, and building external data sources such as Green Button data. It is expected that the OpenEIS platform can then be tailored to apply to residential building analysis and potentially replaced and existing data management tool used in building re-tuning called ECAM.