<p>Value engineering swaps fall apart because nobody checked what the swap touches in the model. A cheaper duct, a different beam or a new finish looks fine on a list, then lands on top of another trade&#39;s work.</p> <p>Three things make a swap survive:</p> <ul><li><strong>See exactly what moves.</strong> Publish the revised model and compare it to the last revision. BidLight shows the differences element by element, grouped by structural, MEP, envelope and interior.</li><li><strong>Pin the conflicts.</strong> Each issue attaches to the element it concerns and carries the sheet and revision it came from.</li><li><strong>Close with proof.</strong> An issue closes only with a screenshot, a tagged user and the model commit that fixed it.</li></ul> <p>Solve it in the model and a clash costs about $50. Find the same clash in the field and it costs $5,000 to $50,000, plus $15K to $50K a week in idle field labour while it sits.</p> <p>The goal is not the cheapest swap on the list. It is the one nobody has to reopen on site.</p>