The Green Book assumes an "Engineer" exists to supervise the work. If the project is too small for a full-time engineer, name a qualified independent person or even the Employer (with careful drafting in the Special Provisions).
The FIDIC Green Book 2017 has been widely adopted in the construction industry for several reasons: fidic green book 2017 pdf
If you are familiar with the older 1999 Green Book, the 2017 version introduces several improvements: The Green Book assumes an "Engineer" exists to