It is possible to change cake formulas, either to improve them or to reduce costs. However, ingredients and quantities can be changed only within certain limits. A cake formula whose ingredients fall within these limits is said to be in balance. Knowing the limits helps you not only modify recipes but also judge untested recipes and correct faults.
Keep in mind that new ingredients and procedures are frequently developed. Cake-balancing rules that have worked well until now may be changed as new developments come along that allow you to break the rules. A baker should be open to new ideas and willing to try them. For example, it was once a rule that the weight of sugar in a mix should not exceed the weight of flour. But the introduction of shortenings with emulsifiers led to formulas with higher proportions of sugar.