The Flexibility Assessment Method Workgroup of the System Analysis Advisory Committee (SAAC) will examine the current power system flexibility assessment methods in research and practice. The workgroup will look to identify gaps in these methods, compare the methods including potentially testing multiple methods on a single data set and describe the merits of the different methods considering the unique operational and planning requirement of the Northwest power system. The workgroup will collect their findings in a report and present this report to the SAAC. This report will help inform the assessment of the supply of and demand for flexibility in the seventh power plan. The public release of the report will conclude the workgroup.