Typically management trying to stick to the timeline, it's easy to get pushed into just getting ut done regardless if it's right or not. What they don't understand is sometimes it's necessary to slow down or take a step back in order to move forward more quickly. Sometimes you end up spinning your wheels and just goin in circles when if given the opportunity to really take a moment and sort it out it would save time and money in the long run. Also, lots of times designers and some engineers work in a virtual world when the create their models and when it comes down to it, depending on the process chosen to actually make the product, you are mathematically limited and also limited by the capability to hold certain tolerances. Tighter isn't always better, however the are too lazy or just not knowledgeable enough to do a tolerance analysis or stack up. How to handle is different everytime depending on the situation and whos involved. It's difficult to argue with someone who doesn't really understand, so it's necessary to help them understand what the limitations are or the particular scenario so they feel comfortable accepting it. Otherwise it's like talking to a wall. So much comes into play, workplace politics, arrogance, elitism... list goes on. we stand our ground as long as possible but sometimes we have to meet in the middle or just completely cover our eyes and pretend nothings happened. When I worked in aerospace my mentor said something that's always stuck with me... It's unnerving to know contracts go to the lowest bidder, then they manufacture product in the cheapest manner, with the cheapest material that still meets spec. The saving grace is that they over do tolerances knowing that they may receive product that's non conforming, however it will still function as intended. It's a lot different in medical due to the FDA, bit at the same time there's so many similarities. .. same shit, different colored walls. It's a constant battle and at leat at my place we are making progress, but it always makes me wonder. There's so many factors that many ignore... temperature for example... temp makes parts swell and collapse... especially soft materials like plastic. Should we stick with the common 68 deg plus or minus 2 degrees? Why? Is an operating room held to the same standards? Hell... the human body is at nearly 98 or 100 degrees... how does that affect geometry of the implants being inserted? Expansion coefficient changes drastically depending on material. The arguments are endless... the progress is slow... I can go on forever lol there are so many scenarios... rest assured that planes will still fly and implants will still function, but to those of us really involved, there is plenty of room for improvment.