Excerpt from an address by Elder L. Tom Perry of the Quorum of the Twelve, "Increasing Our Effectiveness in Home Teaching," Ensign, July 1981, 6

An effective ward home teaching structure will utilize the following organizational principles:

Workload.
Back in the early 1900s when the ward teaching program was first introduced, the workload assignment was eight families. It was found to be too heavy and was soon reduced to six. This was still too much. Three to five was found to be all that could be expected of an effective home teacher. Yet some sixty years later we find wards where the ratio of active priesthood to families is far from satisfactory.

The problem of having units with a shortage of active Melchizedek Priesthood members to teach families probably will only increase in the years ahead. Single parent families resulting from death or divorce and the imbalance of males and females in the Church continue to increase. We must learn how to deal with this problem. There is no pat answer; every ward is constituted differently. But assigning unreasonable workloads of six, seven, eight or more families has proven not to be a satisfactory answer.

Span of control.
Just as it is wrong for a home teacher to be assigned a workload beyond his ability to perform, so it is wrong to assign to a quorum or a group more than the leadership is capable of controlling. The bishop has a right to deploy his manpower to gain the most efficient usage. It is not efficient to assign 70 or 80 percent of the families of the ward to the elders quorum unless they have the strength and the ability to effectively accomplish that workload. It is not efficient for a high priest to drive twenty miles to visit another high priest and then for an elder to drive twenty miles to visit a prospective elder living next door to that high priest.

Of course we want to maintain the integrity of quorum visits to quorum members as much as possible. However, there is in every ward of the Church a large number of prospective elders and single sisters who can be assigned to high priests and seventies, as well as to elders, to equalize the workload. The correlation of their assignments can be accomplished in the priesthood executive committee meeting.