If you want to be a bad product manager, give your requirements to development without any explanation. Their job is just to build what you tell them to build — they don’t need to understand why. Any time you take telling them why the requirements are important is time taken away from actually building the product.
If you want to be a good product manager, articulate to development why requirements are important. Developers and engineers are not just order-takers but an important part of the product development team. In order for the requirements to be fulfilled, everyone needs to understand their purpose and value.
When there is common understanding of the “why” behind a requirement, those responsible for “how” the product can fulfill that requirement — designers, developers, etc. — can come up with the best possible solution. Without understanding the purpose of a requirement, teams will question whether it needs to be fulfilled, whether it needs to be changed, how valuable it is to the customer, and whether there isn’t some other better requirement to be working on.
Mike Lunt calls this The Other Side of Product Management. If one side is “gathering requirements and selling the products to the sales team,” then the other side is “selling the engineering team on the value the new features or changes in the product will have for the customer (and ultimately the success of the group).” He adds that
for a product to be successful, the engineering team must be motivated to implement the product manager’s feedback. Many projects have failed or been plagued by engineering feature creep because the team did not have confidence in the information stream coming from the product manager(s).
There are actually many sides to product management, but this is one of the most important. Good product management requires the ability to understand customer and market needs, communicate them to the product development team, and package the solution as a compelling product for sale. Getting understanding within the team is the bridge that connects the market needs to the solution and end product.