I agree with srg36 that the mentioned parts are very important in the project but are not the most important. I do however understand where rjs84 is coming from because if enough resources are not allocated to, for example, suppliers, then the materials used may be rejected heavily and create a slew of issues down the road. Also, if the vendors don’t want to work with you to consistently provide material that becomes another big issue which will hinder the project schedule. All parts of the project are considered important. Sufficient resources should be allocated to each stage depending on what the circumstances are. Safety measures or plans to tackle issues both known and unknown should be addressed in the planning phase.