several things determine the laying rate/quality.
One is food.. As Kim said, they need at least 16% protein --If you are offering 16% pellets free choice and giving the free choice of corn--they might eat enough corn to dilute the protein in their pellets! So look for higher protein treats, meal worms, really good birdseed (nuts, berries, oats,--the one I feed is 11% protein and I use it as scratch).
Two is seasons/time of year.. they don't lay as well in winter--shorter days--they need 12 hours of light to lay really well
Three is stress-- not having a good ratio of hen to roo, predators--including the owners own animals , illness/health, moving them
Breed-- some breeds have not been bred for production-- Different breeders breed for different purposes..Many backyard flocks are breed w/o thought to what they are breeding-- including egg production and flighty, nasty temperament. They might be gathering ALL their eggs and hatching them w/ out thought of what they are really breeding. And show quality birds might be bred for just looks/ conformation instead of egg laying qualities.
And age! Younger hens don't lay on a reg. schedule, it's haphazard at best.. Older hens might be not lay on a reg schedule...