You can't manage a project if you have no idea about the effort and risk associated with each piece of work. A typical job for a PM is to negotiate solutions wi

You can't manage a project if you have no idea about the effort and risk associated with each piece of work. A typical job for a PM is to negotiate solutions with a customer, in that case they need to estimate work items relatively accurately in real time to do a good job. Non technical PM's will either make up bullshit estimates and then pressure their developers to follow through or they will be very bad at fulfilling customer needs since they constantly need to verify everything with the devs.