Shift Staffing Configurations

There is no more common question among comm center administrators--and even dispatchers--than those about staffing. How many dispatchers should we have, how many people should be taking phone calls? How can I spread out 12 dispatchers on a 10-hour schedule? On and on....

There is no standard formula, mathematical or otherwise, to that question. It can only be determined with a time and task study of your center, and an evaluation of your agency's performance goals. We've tried to answer some of the questions in this section. However, do not look for the answer to the one burning question that everyone wants to know: How many dispatchers should my comm center have? You have to perform some survey work before that question can be answered.

We've attacked the most important areas: shift staffing (How many people do I need to staff X dispatchers on each shift?), shift configurations (What days and hours should the staff work?), and calltaker staffing (How many calltakers do I need to answer X number of calls?). These three questions can be answered with formulas. Besides lots of our own resources, further down the page we list Web sites that offer assistance, along with a list of companies that market software for shift scheduling.

By the way, the nation's public safety comm centers continue to suffer through a staffing shortage. There have been fewer and fewer applicants, and many veteran dispatchers are retiring--or just leaving. Check these resources first for perspectives on the staffing crisis:

We've posted our recommendations for solving the on-going staffing crisis faced by America's public safety comm centers.
We've collected experiences and feedback from dispatchers their schedules and staffing.
In August 2005 APCO's "Project RETAINS" issued its final reports and documentation for helping to determine proper staffing--it's a must read.

The most common question among comm center administrators is, "How many dispatchers do I need?" This question focuses the tasks, number of consoles and other issues, and cannot be condensed to a single math formula. One would have to perform a time study of the work now being performed, determine the workload for each hour of the day, and consider the agency's performance goals (answer all calls within 10 seconds, etc.) in order to determined how many dispatchers to staff on each shift.

In many cases, the number of personnel can be figured pretty simply from the required tasks of an ordinary time period, for an ordinary day:

you have two radio channels that need constant and individual attention (2 persons)
you have a warrant/teletype position that handles field requests via radio, enters stolen vehicles, etc. (1 person)
you have 6 in-coming 911 lines and 8 administrative lines, have an automated attendent that filters out most administrative calls, and you want to be able to handle 3 simultaneously 911 calls (3 persons)
you have an alternate radio channel that needs constant monitoring for officers requesting tows, callbacks, etc. (1 person)

This means you'll need seven persons on-duty to physically handle tasks. With this figure, you can then factor in several variables:

some periods of an ordinary day are busier than others, and you may need additional telephone support
some days of the week are busier than others, and you may need additional telephone support
during busy periods, you may need additional radio support.
to account for breaks, you may need an additional full-time or part-time person during a 24-hour period.
to account for 24-hour operation, you'll need more staff
to account for sick leave, vacation and other leave, you'll need more staff

All of this will lead you to learn that it takes 25+ persons to fill seven seats every hour of every day.

You can use much more complicated time-study techniques to determine how many different and simultaneous tasks a dispatcher can perform, and how busy they typically are. However, for most comm centers, the basic staffing numbers are pretty obvious. It's the variable workload and leave factors that are often tough to determine.

Relief Factor

Once you determine how many dispatchers should be on each shift, one can determine how many staff is required to fill those necessary positions. The formula is based on the simple fact that you need one full-time person to fill each position, plus some fill-in position (another shift, part-time worker, etc.) to staff that full-time person's days-off, vacation and other leave. This Relief Factor has been standardized in the private sector as .7, thereby making the number of persons to fill one full-time position as 1.7. [how to figure Relief Factor]

Here is the formula for determining total staffing:

P= Positions you have determined need to filled on all shifts (4 on days, 5 on evenings, 3 on nights)

V= Vacancy Factor (takes into account the weekly days-off, vacation, sick leave, etc.)

P x V = total number of staff

In the above example, you have a total required staff of 12, so...

(4+5+3) x 1.7 = 20.4

In this case, you would hire 21 persons, and then move on to the next question, "How do I assign these 21 persons to fill the required staffing?" This can be the most complex problem to solve.

By the way, we've also seen the factor 5.1 used to represent the number of persons it takes to staff one position 24 hours a day, 7 days a week (spread out over 3 shifts). If your staffing is identical on each shift, this figure would result in the same total as using the 1.7 vacancy factor used above. For example:

3 persons required at all times of the day

3 x 5.1 = 15.3 total staff

You would then hire 15 (or 16) persons and assign them to cover the three shifts. This 5.1 factor would not be useful when variable shift staffing is needed (such as covering busy periods).

There are many ways to configure shifts at a comm center. However, all the possibilities revolve around several standard issues:

From these considerations, there are two primary configurations issues for an administrator:

Both of these issues are affected by the number of hours that a dispatcher works per shift: 8, 10 , 12 or 24 hours.

One of the most common questions among public safety comm center administrators is, "How do I calculate how many dispatchers I should have?" As we mentioned, this is difficult for several reasons, not the least of which that there is no standard staffing level for comm centers, and no mathematical method of taking into account all the variables involved and coming up with a reasonable figure. However, we have assembled the following resources to give you a start on your calculations.

We've downloaded a chart created from Erlang theory calculations, reassembled it into an Acrobat (pdf) document, and posted it here to help you determine how many dispatchers you'll need to answer telephone calls--it doesn't take into account any other activities, such as radio dispatching, outbound calls, paperwork, CAD typing, etc.--only answering telephones. Nevertheless, it's useful to obtain a ballpark staffing figure, especially if you have a dedicated call-taking operation.

Download the chart, print it out and follow the instructions printed on it. Here they are:

All (I think "all") of the formulas for staffing predictions are predicated on establishing the existing average length of call and using that as the basis for further calculations. I believe this assumption is incorrect, since there is a failure to determine if the average length of call is appropriate or justified.

An agency for which I am working now has an average length of calls of 4-1/2 minutes and has elaborately built staffing around that statistic. There is no justification for that length of call, other than that is what it takes. Since the length of call averages can be translated into budget costs, every second trimmed off the average can save the agency money.

My view would be to take the busy hour, transcribe all of the calls, and determine from those transcriptions if the average handling time was appropriate. Generally, the calls can be objectively evaluated and average handling times can be adjusted accordingly.

Some agencies have concluded that the average handling time is less important than the agency's ability to provide the highest level of customer service. If the call can be concluded in 60 seconds or 60 minutes is less important than the impression left with the caller that the agency performed an exemplary service. Of course, such service comes at a cost.

Some agencies have found that a two-tier answering service can work well to properly manage calls, maintaining a good customer service while controlling costs. Such an arrangement specifies that the call taker must complete the call within (for example) two minutes, and if it cannot be, must be transferred to the second tier. The second tier may consist of a small unit of personnel more skilled at call handling, but at a classification level below that of supervisor. Call handling averages can then be categorized and evaluated, with accurate statistical data separating easy to handle calls from those few that require additional time.

We've collected various Web pages over the years that provide some assistance in shiftwork, staffing and scheduling. Your first stop for resources should be:

From the material we've collected over the past couple of years, we came across an incredibly complicated schedule that's actually worked by dispatchers. We've mapped it out with color coding and present it in Acrobat (.pdf) format. We also have posted a collection of circa 1976 schedules that were compiled by APCO [Acrobat pdf format 1.8 Mb!].

Also check the example of a 10-hour shift schedule that features rotating days-off, from the Cincinnati Police Department comm center.

Most agencies have a method or scheme for allowing dispatchers to select the shifts they want: the time of day to work, and the days-off to have. In most cases, these schemes were originally devised by the dispatchers, and then formalized by a union agreement. The agency almost always agrees to these schemes with the condition that the police or fire chief, or manager of the center can re-assign personnel based upon the needs of the agency (such as going to 12-hour shifts for a large emergency or staffing shortage, shifting trainers to another shift, not allowing an all-rookie night shift, etc.).

In all cases, the procedures should be typed up, written out, posted, signed, acknowledged, filed, etc., with all personnel. Everyone must know how the procedure works, and the implications of their selections, decisions and choices. There will always be disputes, either through misunderstandings or interpretation of the procedures. Just like contract law, anticipate problems and cover them in the procedures.

In most cases, shift selection is done in seniority order. That is, the person with the most seniority is allowed to select their choice of shift first, followed by the next person. Persons at the end of the list have very little choice of shifts, and the last person--well, they're stuck. Shift selection can occur annually, or at some more-frequent interval.

Other agencies rotate dispatchers among the 3-5 available shift hours, and allow the dispatchers to select their days-off by seniority. Typically, mandatory rotations more frequently than voluntary ones, on the theory that the agency is "spreading out the misery" of working evenings, nights, etc. Under this situation, a dispatcher can anticipate what hours they'll be working, although they still can count on certain days-off until the selection process is over (or they have very high seniority).

By the way, vacation selections are frequently performed the same way: by seniority, at least one year in advance. That is, dispatchers would select one year's worth of vacation in 2002 during November 2001. Vacation can either be selected all at once (whatever vacation time the dispatcher has accrued), or in "rounds," during which they can pick some maximum amount (80 hours each round, for example). The rounds continue until no dispatcher has any more vacation to select. The "all at once" approach favors the most senior personnel (they get best pick), while the "rounds" approach gives the lower seniority personnel at least some chance of obtaining a decent summer week off.

The agency may also apply other limitations to the vacation selection, including that you can only pick contiguous weeks (no one-week-here, 3-weeks-there), no more than three (or whatever) dispatchers off at once, no changes after selecting, a canceled week is offered to dispatchers with less seniority (on down the list), etc. Again, much of this procedure could be regulated by union contract.