You should document (in writing) any design changes or delays caused by the client.
This is very important for claiming cost or time extensions.
A good change management system is important. Spreadsheets can suffice for small projects with a small number of changes, but for larger projects, a good database system will help reduce the time required for change management.
You will need to record things such as (these are in no particular order):
- change title
- time delay
- extra costs (design, construction stage services, extra construction costs, administration costs, extra workshops, safety)
- who requested the change (which person from the client organisation
- approval status
- risks associated with the change (extra risks arising from changes in the design)
- change details
- why it is needed
- name of responsible person
- associated design drawings or packages
- cost codes (linked to your accounting system)
- date of change request
- change impact (minor, moderate, major)
- date completed
It would be ideal if these can all be entered on one page in a system. You should then be able to output reports showing just some parts (say change title and cost), without having to duplicate information into spreadsheets etc.
You do not want to have multiple systems or spreadsheets that all have different versions of the information and are not linked.
There should only be one place where all the information on the change is recorded.