I dont think you will find an agreed definition. LOLER does not provide a description as to what constitutes a "complex" lifting operation. However the requirement for a risk assessment and lifting plan applies to all lifts not just complex ones. LOLER requires that for complex lifts the plan should be reviewed prior to each lift. In light of this I would suggest that a suggested definition of a complex lift would involve one where the size and shape of the loads will vary and where the environment of the lift is changeble, the route of the load varies introducing the possibility of obstructions and potentially different hazards with each lift etc. In other words any lift where a day to day risk assessment or method statement would be redundant. I am sure someone will provide a better definition/opinion as to what constitutes this but this is how I would interpret this requirement. Regards

There used to be a good explanation on the CPA site but it seems to have disappeared. BS7121 Part 1 is what you need a copy of. Complex Lift. More than 1 crane Hazardous Area like Petro Chem, Nuclear plant, Steel Works and more. Lifting People. Railway Lines. Heavy or Bulky Loads and many more. As mentioned most every day lifts would be a standard lift when it gets out of the ordinary you would be looking at Complex. Hope this helps. Ta Alex

With reference to BS7121 you will also need an appointed person to write your lifting plan Regards PaulR