I've had the opportunity to look at hundreds of proposals from engineering, environmental, and architectural firms over the years. It's remarkable how similar they are in many respects. Unfortunately, most of those similarities are shortcomings that contribute to low win rates. I suspect that your firm's proposals also share at least some of the following common deficiencies:
Lacks client focus. The client, not your firm, should be the centerpiece of your proposal. Above all, you want to demonstrate an understanding of the client's concerns, needs, and priorities; what solution is best for the client's situation and why; how you're going to deliver that solution in a timely, economical, and responsive manner; and what the expected outcomes will be.
Most proposals, of course, violate this advice. And clients promote the problem with their misguided RFPs. They suggest that qualifications will be the primary factor in selecting the successful firm. Do you believe that? Clients make their selections based on comfort, familiarity, chemistry, and confidence that the proposing firm really understands their needs and can effectively solve their problems. Of course, they still expect you to comply with the RFP!
Lacks a central theme. The best proposals have a story to tell, a central narrative that weaves all proposal elements into a cohesive message. The basic storyline usually involves linking the client's concerns, needs, and aspirations with what your firm specifically has to offer. Most proposals are a paint-by-numbers response to the RFP--and little else. They are often prepared by multiple writers who have made too little effort to define a common thread among their individual contributions. The results come off as piecemeal and unfocused.
Is a difficult read. Proposals have certainly gotten better looking than when I started writing and studying them in the 1980s. The advent of color, better design, and more graphical elements has made a huge difference in their appearance. But I'm not sure they've come all that far in the critical area of functionality. They're still not that well written, are difficult to skim, and often aren't very easy to navigate.
A user-friendly proposal is characterized by clear writing, ample headings, effective graphics, and an intuitive organization. This not only makes it easier for the client to review, but facilitates better communication of your message.
Doesn't have an executive summary. I know, the RFP didn't ask for one. But if you put one in your proposal, I can pretty much guarantee it will be read. And if it's a good one, it can help you win. An executive summary captures the essence of your proposal in a few pages. It's usually read first (where it should appear in your proposal, of course). This allows you to put your strongest message front and center, regardless of how the RFP instructs you to order your response.
Is more tactical than strategic. Describing how you're going to help the client is the most important part of your proposal. But in most proposals I've read, this is the weakest section. If the A/E firm wasn't talking with the client before the RFP came out, it's usually evident here. The scope of services looks like a recycled write-up from another proposal with a few details changed (because, well, that's what it typically is).
But even when the firm knows the project well, the description of the work often fails to demonstrate it. A common reason for this is providing a scope of services without adequately describing the project background, objectives, and approach. In other words, it's tactics without strategy. Strategy involves linking needs and solutions, understanding the bigger picture, connecting to business-driven goals. Scope of services is a contract issue; project insight and strategy wins the day.
Is overly conservative. Another reason that proposals fail to demonstrate project insight is that the submitting firms are often reluctant to share what they know. There are two primary reasons for this, both unwarranted in my opinion. The first is a fear that proposal contents could be shared with competitors. That great strategy you could have proposed might have been implemented by the successful firm the client was going to hire anyway. That may happen on occasion, but I remain unconvinced that the threat is worth reducing your chances of winning by holding back your best stuff.
The second reason is the natural reluctance of many technical professionals, engineers in particular, to share ideas without adequate backup. "I don't think we want to offer that option in our proposal," I've been told on several occasions, "because we don't have enough information to know for sure." Why not offer it as a possibility, then? Clients value your insights--even your educated guesses--when sorting through potential solutions to their problem.
Don't be afraid to include the occasional tease in your proposal. The tease--sharing just enough information to create interest--has long been an effective marketing and communication technique. It doesn't commit your firm to anything, but it just might help get you to the shortlist.
Shouldn't have been submitted in the first place. Many proposals fail for reasons other than content and design. You lacked a relationship with the client, there was an entrenched incumbent, there was an unresolved service problem--any number of factors that should have resulted in a "no go" decision. You knew your firm was a long shot, but thought it was worth a try nonetheless.
Unfortunately, whatever improbable chance of winning you might have had was undermined by the shortcomings mentioned above. That's why it's best to limit your submittals to those that you have a reasonable chance of winning and can commit to doing them the right way.