SIAMS stands for the Statutory Inspection of Anglican and Methodist Schools, and at Church of England schools like St Richard’s it runs alongside Ofsted inspections. It’s a requirement under the Education Act 2005. The SIAMS inspection only looks at the faith aspects of a school’s life: it evaluates how effectively the school's Christian vision impacts the school community, helping both pupils and adults to thrive, and to live up to its foundation as a church school. It examines Religious Education (RE), Collective worship (assemblies), and the school’s overall culture.
You can read more here: https://www.churchofengland.org/about/education-and-schools/church-schools-and-academies/siams-inspections