This chapter introduces Problem Frames as a framework for the analysis of sociotechnical problems. It summarizes the Problem Frames approach, its techniques and foundations, and demonstrates, through theory and examples, how it can be applied to simple sociotechnical systems. The chapter continues with the description of an extended Problem Frame framework that allows the treatment of more general sociotechnical problems. This extension covers social components of a system — individuals, groups or organisations — bringing them within the remit of the design activity. The aim of the chapter is to make the Problem Frames framework more accessible to the software practitioner, especially those involved in the analysis of sociotechnical problems, as these problems have so far received only scant coverage in the Problem Frames literature.