According to ACI 214-77 (References 2) the Overall Standard of Concrete Control is related to the Standard Deviation of a set of Test Strengths and to the Class of Operation as in the following tables.
| General Construction Testing | Laboratory Trial Batches | ||
| Standard Deviation (psi) | Standard of Control | Standard Deviation (psi) | Standard of Control |
| below 400 | Excellent | below 200 | Excellent |
| 400 to 500 | Very Good | 200 to 250 | Very Good |
| 500 to 600 | Good | 250 to 300 | Good |
| 600 to 700 | Fair | 300 to 350 | Fair |
| above 700 | Poor | above 350 | Poor |
These values are obtained from table 3.5 Standards of Concrete Construction of ACI 214-77.