Heyho!
I've been discussing the following sentence with my girlfriend for days. For me (the author :)) it is understandable. She thinks that the point is hard to get and the sentence could be better constructed. Neither she nor I am native speakers. What do you think?
Therefore, structuring and planning technically complex products together with engineers have always been successful and productive.
Thanks in advance! Florian
Since you supply the sentence here without context, you don't give readers any outside help in making the sentence thoroughly intelligible on a first (or subsequent) reading. With regard to full coherence, the sentence's biggest problem, in my opinion, is that the "structuring and planning [of] technically complex products" occurs without there being anyone or anything in sight to do it, "together with engineers." And because the sentence doesn't flow well, readers have plenty of time to notice the absence of this crucial actor as they slog through the wording.
When I try to make sense of the original sentence,
Therefore, structuring and planning technically complex products together with engineers have always been successful and productive.
as a stand-alone found object, I find myself reordering and revising its components to look something like this:
Therefore, working [or my work] with engineers to structure and plan technically complex products has always been successful and productive.
This revision accomplishes a couple of things: (1) it brings the engineers forward in the sentence as collaborators (with the unnamed person or persons) in the successful work, which avoids forcing the reader to decide what to do with the awkward and poorly positioned phrase "together with engineers"; (2) it defuses the distracting controversy over whether "structuring and planning" should take have or has, and effectively yokes them (in the form "to structure and plan") to the newly introduced verb work, where they make immediate sense.
(In reading over the other comments and answers to this question, I discovered that Edwin Ashworth had suggested a wording very similar to mine back on February 2. I would happily have upvoted his comment as an answer if he had submitted it as one.)
My revised sentence still doesn't clarify who is "working with engineers" (unless you accept the alternative wording "my work" in place of "working"). Now, however, the absence of that information is far less noticeable because the sentence trots along so briskly.
In fact, the weakest aspect of the revised sentence is probably the echo of products in the final word productive. But this criticism is an aesthetic quibble, not a matter of coherence—and in any event you can easily resolve it either by changing productive to something like effective or by dropping "and productive" from the sentence altogether.
I would use has rather than have.
I also agree with Edwin that the structure of the sentence seems clumsy and should be revisited.
The use of therefore with a past tense jars to me. "Therefore... will be/is likely to be successful" would work, or "Consequently...has been..."
It's loosely understandable; and it could be better constructed. As others have pointed out, though, it's hard for us to fix it, because it's only loosely understandable! We need more context.
Here's an attempt:
Thus, complex products may be more successfully and productively planned and designed when engineers are involved.
I agree with Erik that the sentence should be reworded for better clarity. However, a quick fix would be to add "our" before "structuring."
