My first thought: This is a very big problem space to be tackling all at once. Massively huge.
I could see it taking a lot of engineering time to build out a featured product, which has parity with the incumbents at the things they do well. Also your target customers are very process oriented, so you've a big challenge to sell to them. For any given engineering application, you're probably going to be missing some features or feature-richness they consider 'key', for at least the medium term.
Unless something has changed that means they can achieve their needs with a lot less functionality? E.g. Spreadsheet software, by virtue of the inherent power and simplicity of the metaphor, turned out to be good at a lot of things, and killed a lot of special purpose apps. Even then it took a lot of resources to write an early spreadsheet package. And its really difficult to build horizontally successful products like that.
So the common pattern to tackle this is to pick a really narrow niche you can specialize in and dominate, within the wider market. Ideally a new or underserved niche, or one that has changed recently in some important way, which means it isn't being served optimally by existing solutions. And getting enough better than an incumbent in just that niche that you can get some traction, get funding, bootstrap your development, and [>5-10 years later] eventually build the more general product.
Have you thought about doing that? Its not always the best thing to do, but it should be given a lot of thought?