Some companies have dedicated Business Developers, and others leave the task to their project managers. Regardless of your background, if you are assigned the role of Business Developer, then your job is not only to find potential bid opportunities, but also to gather intelligence about the customer, the opportunity, and the competition that will be crucial to winning the opportunity.
Once a lead is identified, you must qualify it --- prove that it is real and that it is worth pursuing. Your company should not bid on every opportunity it stumbles across. You can help by gathering the intelligence needed to help your company decide which leads to pursue. Any intelligence you gather that indicates an opportunity is not real or worth pursuing is just as valuable as the intelligence that makes that opportunity look good.
After the lead has been initially qualified, when it is time to begin investing in its pursuit, the company should make a formal review. If the company decides to invest in the pursuit, it will assign a Capture Manager to the opportunity. The Capture Manager will be dedicated to winning the opportunity, whereas a Business Developer will typically continue to focus on identifying new leads. You will need to help get the Capture Manager up to speed on the opportunity, customer, and competitive environment. The Capture Manager will continue to need your input throughout the process.
When the proposal phase begins, the Business Developer should personally make sure that the proposal reflects what the customer wants and what you know about the competition. Your knowledge about the opportunity, customer, and competitive environment goes well beyond what is in the RFP and is vital --- no one can do the job in your place. Business Developers rarely take a writing role in a proposal effort, but if you want to win, you need to make sure that those who do have writing assignments take into account what you know about the opportunity, the customer, and the competition. The proposal that does the best job of speaking to what the customer actually wants (regardless of what it says in the RFP) is the one that is most likely to win. Your job is to give your company that edge.
You will do most of your work before the RFP is released. Once the RFP is released, the customer may no longer be willing to talk to you, so you must anticipate the questions that people will have during the proposal process and get the answers before the proposal even starts. When the RFP is released and people ask questions that you didn't anticipate, try your best to get answers. If the company has to proceed without answers, you may be in the best position to guess what the answer should be.
Preparing the proposal will require addressing many, many tradeoffs. Your understanding of the customer's preferences should be used to help the team make the decisions the customer would prefer. You may be the only one on the team with that kind of insight. Participate in the strategy sessions and offer your insight. Then read the proposal and make sure it speaks to what the customer wants. The technical staff working on the response will have a tendency to completely focus on RFP compliance. Frequently, companies produce technically compliant proposals that don't tell a story or offer the customer any insight beyond what was supplied in the RFP. You need to coach them and give them the information they need to make sure that your story makes it into print. If it doesn't, then all of your careful positioning and work may have zero impact on whether your company wins the opportunity.