Resources production is running smoothly. However, low Production Rate is a drawback to the total output. You are allowed to adjust Production Rate manually in Town Hall. When you need more idle population to train for the army, you can switch down the rate a little.
Click Town hall in your city, and select tab "Production". Adjust Production Rate from 80 to 100.
Adjust Production Rate: Food 100, Lumber 100, Stone 100, Iron 100.