I am a governor of 2 schools and a Trustee in a MAT
More importantly I advise governors on HTPM- I do about 30 a year.
Assuming not in a MAT
You set a range based on the number of pupils. Governors should review this annually a part of the adopting of the pay policy- very few GB do this! The STPC outlines the processes.
www.gov.uk/government/publications/school-teachers-pay-and-conditions
However HT recruitment is very hard (I also do a lot of those) and in my experience most Heads are now out of range. Some GB do this by extending the range and other just find a way to make additional payments within the pay policy.
The expectation is that they move through the range unless there is a capability issue. The Dfe issues advice about teachers in the pandemic and this should be applied to HT as well
DfE Guidance 3rd June 2020 states, maintained schools must continue to adhere to the School Teachers Pay and Conditions Document (STPCD), which includes the requirement to ensure that all pay progression for teachers is linked to performance management. However, we would expect schools to use their discretion and take pragmatic steps, to adapt performance management and appraisal arrangements to take account of the current circumstances…..Schools must ensure that teachers are not penalised during the appraisal process or in respect of any subsequent pay progression decisions as a result of partial school closures, where this has impacted on the ability of the teacher to meet fully their objectives.
You will have a pay policy which outlines how additional payments can be given.
Ignore the advice about SMART targets. There has been no data for 2 years and 2022 will be unviable. I set again the Ofsted criteria for good (or os for a few schools) and the 2020 HT Standards. It is an art not a science. They may link to the SDP.
HTPM is the opportunity to talk about the wide performance of the HT. Governors should focus on what the HT is doing well and if there are any areas that could be improved (not based on your view as a parent ie not give more homework to Y4) . It is often the ONLY time that anyone tells you that you are doing a good job as a Head- except when Ofsted pop up every 5 years. Focus on that- prepare something to say and make sure that you say it and it is recorded.
You should have an external adviser who will support you through the process. Do You?