Table 1.

Factors affecting operation time

Factors	Assessment
Case number	Chronological order Moving average method Cumulative sum analysis (CUSUM)
Surgery case mix	All consecutive cases One type of surgery only (e.g. rectal)
Hybrid surgery	Laparoscopic mobilisation of part of colon Total robotic approach
Experience	Open colorectal surgery Laparoscopic colorectal surgery
Surgical simulator training	Proficiency-based learning
Advanced technology	daVinci Si or Xi robot
Standardised surgical protocol	Dedicated team
Case complexity	Body mass index Colon or rectal resection Cancer tumour stage Female or male pelvic case Extent of inflammation