What is common cause of formwork and scaffolding failure during construction?

Question

improper design of formwork and scaffolding, not adequate braces and supports, improper handling, corrosion of material is several factor of formwork and scaffolding failure. it is estimated that more than 3000 accidents involving falls from scaffolds and 30 fatalities

Answer 1

I believe that you have covered it all. "Improper handling" covers my first thought; workers carelessness by not following safety guidlines

Answer 2

Well, it seems you came close to answering your question.  But are falls a scaffolding failure?   For me failure means that the scaffolding sagged or fell - which may result in injuries with or without falling as when the failing scaffolding falls on a worker on the ground.  I would think that major causes of failure as I defined it would be inadequate or failed attachments to the building and failure of ground support for the structure.  Question needs to be improved to define what you need in answer and avoid conflict between question and detail.  

Answer 3

Improper assembly seems to be a big one.  Workers often neglect to install the internal diagonal from upper corner to opposite lower corner when it comes to scaffolding.  Formwork usually fails by inadequate bracing at the bottom as hydrostatic pressure builds.  This can be mitigated to some extent by allowing the concrete to set up a bit before pouring the next layer.  For earth formwork, you have to be real careful about expansive clay becoming saturated and overwhelming the bracing as it expands.