If I understand your question correctly, you want to educate your HODs on what PMS is all about and how to go about it. We were also working on similar lines to educate the HODs. First, we studied our normal process, then external best practices, and arrived at a process flow.
Option 1 / Normal Process:
Goal Setting → Performance Appraisal Discussion → Rating → Training Plan → Performance Linked Pay
Option 2 / R&D Process:
Goal Setting → Performance Appraisal (60% to the tangible & qualitative output) → 20% to the stakeholder evaluation (180° evaluation) → 20% Potential Of the Individual → Derive at the Competencies → People Development → Guide to arrive at an IDP → Subjective Rating → PLP as per the rating and locating the same in Bell curve Bandwidth → Plan towards vertical movement or horizontal movement.
This is just at the implementation stage, so the next step to implement a new process would be educating the new and existing HODs, launching the process, ensuring the HODs internally communicate to the stakeholders, and facilitate the HODs and employees to adhere to the process.
In a medical industry, the KRAs of each role and their achievable targets can vary, so you will have to relate the process with the same. Other aspects like stakeholder feedback (Doctors' Feedback / Medical Store / Customers, etc.) and behavioral aspects would be the same for all industries.
I request others also to evaluate the same and provide your views.