Counting & Estimating Software Lines of Code SCEBOK
Here are my slides 2017 estimating source lines of code that will be contributed to the ICEAA software costing body of knowledge. It is important to note that Galorath / SEER is size agnostic. Lines of code can work in many circumstances, functional sizes can work well in many circumstances as can other size measures.
There are people who love source lines of code and people that hate them. I have seen people get into big trouble making up SLOC estimates. And I have seen people do a great job of estimating from properly counted analogies or estimates that understood appropriate SLOC counting standards.
Some claim functional sizing is superior to SLOC. Most of these have not taken the care to study and estimate SLOC appropriately.
Of course functional size sizes are excellent. In many ways they are better then SLOC, certainly when the application is simple web based or IT based. But that is a blog for another day.
I have blogged on SLOC before. This might be worth a look.