There are many situations, from recruitment to promotion to redundancies, where employers make selections between people. You often hear people talking about the importance of doing "Equality Impact Assessments" and checking for discrimination, but I've always struggled to get guidance on how to actually do this.
Professional statistician Nancy Carpenter has worked with me to produce a guide to checking for discrimination in selection. It covers everything from how to get hold of data through to how to present it to your employer. I'm aware of several cases where analysis similar to what we describe has worried employers enough that jobs have been saved. I'd be interested to hear experiences from other activists.