PSA: Here's the reason your sawpit isn't working in Manor Lords
It's all about the oxen, you see.
Having trouble producing planks in Manor Lords? You're likely just starting your first settlement; planting down burgage plots, building a well and a marketplace, and deciding where your fields are going to go. Maybe you're even contemplating building a church, but you're having trouble producing planks at a consistent rate. Sometimes you'll get a few, but most of the time it seems like the family you put in the sawpit isn't doing anything.
Here's why: your sawpit needs a steady supply of timber to produce planks, by which I mean, those massive logs that your logging camp chops down and your ox hauls off to any nearby construction site. Logs can't be moved by your villagers, which is why the logistics of your settlement rely so heavily on your oxen. The reason your sawpit isn't working is because it has no logs in storage to turn into planks and your ox is busy doing other jobs, such as hauling timber from the logging camp to buildings.
So, what can you do? There are a few solutions that'll help you get the sawpit working more consistently, but I recommend you upgrade your hitching post and buy a second ox. This is something mentioned in our Manor Lords tips guide; use your first few planks to upgrade your hitching post into a small stable with extra capacity, then click to order an ox using some of your starting regional wealth.
This will speed up timber transport in your town, especially if you assign a family to the hitching post—something I also recommend. This should free up an ox to transport timber to the sawpit. If you're dead set on getting more planks, you can also select the building, click the 'advanced' tab, and set a permanent livestock assignment, meaning that one of your oxen will be dedicated to hauling timber to the sawpit. You can also make its job easier by placing your logging camp, sawpit, and hitching posts close to each other.
The only issue with buying a second oxen early on is it eats into your starting regional wealth. This might mean that you struggle to establish a trade route to earn more, unless you research the trade logistics technology that limits the cost of setting them up to 25 regional wealth. If you don't want to buy a second oxen so early, then just make sure you aren't building a million different things at once, since this will keep the ox busy indefinitely, meaning it never has time to bring timber to the sawpit.
As your town expands and your plank costs increase—if you build a bowyer's workshop for example—it's worth building more stables, buying more oxen, and assigning more families to look after them to make sure they get resources where they need to go. Oxen really are the logistical lifeblood of your town, determining how fast any construction effort or building upgrade is accomplished.