Thanks for this good piece of work. Just some suggestion for you to consider:
1. Summary for Total and Total are basically the same thing. Suggest to keep the first one and group them for easy reference.
2. Test your logic for all the months – if tested correct please provide a clean copy.
3. Lock the cells which we do not allow them to change.
4. For read me, can we expand the instructions into how to update this sheet. For e.g. source of data, PIC, timeline etc.
This is really a good start and keep it up