below. Assuming that the duration of the contract is twelve months, the
estimated minimum total population is the estimated monthly minimum
multiplied by twelve - (456 X 12) and is equal to 5472. An alternative
approach is to deduct 20% from the historical population given for the
twelve month period which gives an estimated minimum population of 5681.
4-520 Sequential Numbering of of the Work Locations. When activities are
spread over a large area, such as is the case with housing maintenance,
trash pickup, janitorial services, and grounds maintenance, careful
numbering of the locations at which the work is to be performed makes the
QAE's job much easier. Generally, the locations should be numbered in a
sequential order corresponding to the most efficient route the QAE would
follow. This numbering is recommended irrespective of the type of
surveillance planned and provides a method for preserving a record of the
locations actually inspected .
Consider for example that a contract requires the emptying of garbage
containers. The fact that some of the containers are to be emptied once a
week and others are to be emptied more frequently does not effect the
numbering scheme. Beginning at a point at which inspection could be
expected to begin, (close to the field office for instance) the most
efficient route required to travel from container to container is
determined based on the assumption that all containers are to be inspected
on any particular day. The containers are numbered sequentially along the
travel route. The sequential location numbers may be shown on drawings or
summarized in tables (see Figure 4-2).
The failure to logically number the work locations can cause a great deal of
unnecessary additional travel. When random sampling is used, this
additional travel is often erroneously attributed to the cause of random
sampling, when in fact, the additional travel is caused by failure to
properly number the work locations.
4-600 SEQUENTIAL NUMBERING OF THE POPULATION
4-610 General. Once the population has been identified and the work
locations numbered, the individual service occurrences in the population
must be assigned sequential numbers so that each service occurrence in the
population can be distinctly identified from the rest of the population.
Sequential numbering of population is not required for 100 percent
inspection although the work location should be sequentially numbered as
outlined at 4-520. Sequential numbering use of the population is essential to
random sampling techniques and should be considered for use in connection
with planned sampling.
The way in which the sequential numbering is carried out depends on whether
the services are scheduled or unscheduled
4-620 Sequential Numbering - Scheduled Services. Scheduled services must
besequentially numbered with reference to the calendar.