It depends on different factors, like:

• the complexity of the plant (mainly energy recovery),
• a new or tailor made installation, or an incinerator which has already all drawings ready
• People: all drawers and engineers available? Or occupied with an other order?
• Suppliers: are they ready?
• Etc.

Generally:

1. Drawings : 2 - 4 or more months
2. Equipment supply : 4 - 7 months
3. Assembly (also during equipment supply) : 4 months
4. Start-up : 2 months
5. Fine tuning : 2 months
6. Guarantee

For a small incineration plant you may count 12 - 14 months
For a big incineration plant you may count 24 months or more.