Instructions must be in writing.
An Instruction can be required on Site or yard for all sorts of reasons such as safety, access, errors, corrective actions rework, interference or coordination issues.
The instruction is best given in writing and if this means a change to the contract then the Variation or Claim procedure shall be followed.
Instructions shall be recorded in a Instruction Register which shall be maintained and discussed between the parties. The number of instructions can provide a trend for Site or other performance issues and their causes.