Talking Point | Tips | How To10 May, 2001

Welcome to Issue 2 of SIMUL8 User!

To put together this issue we looked over a number of consulting projects we conducted in Call Centers, and have highlighted the main technical areas that are common to them all. We are always interested to hear comments from and exchange experiences with other SIMUL8 users, so with anything you want to share, discuss, or find out more about.

Talking Point

There has been an increasing interest in simulation as a tool for planning Call Centers and optimizing call center performance - there are even books written about it*.

There have been tools around for a long time, but simulation is a great way of quickly and relatively simply creating an accurate representation of the real flow of calls, agent utilization, and performance standards, while getting around the limitations of "old style" tools like Erlang formula. In short simulation allows real world recreations of Call Centers to be built more quickly and easily.

So, looking back over a number of Call Center related projects in a variety of industries (retail, utilities, emergency services) here's a summary of what the key inputs and outputs are, and how to put together a simple Call Center simulation.

These inputs and outputs are usually supplemented by some other information, like financial information, and the proportion of calls that pass on to second line help, into an Outgoing Call list, or result in back office work and wrap-up time. Trunk Utilization could also be a key result.

Before getting to these, however, a getting started simulation needs to be put together. The simplest case could look like this:

In this simple Call Center, 2 agent groups have calls routed to them by a "switch". The caller will be given an "what is your call concerning" option by the switch and asked to press a button on the telephone keypad, before they pass on to a queue to wait for an operator to deal with their call. If they wait too long (say more than 30 seconds) they hang up. Outputs from this include the achievement of a service standard - for example "it is our mission to answer 90% of callers within 10 seconds and 95% of callers within 20 seconds"

Even this simple simulation allows "what-if" games to be played. The key result is that there is a "non-linear" trade off between hang-ups, achievement of service standards, and operator utilization. This means that as operators become busier it becomes increasingly likely that callers will end up waiting for too long and hanging up. In data terms this means that when operators are relatively under used a 5% increase in utilization could have little impact on service standards and hang up numbers. However, when the operators are already busy as little as a 5% increase in operator utilization could lead to a 20% or greater fall in the number of calls handled inside the service standard and corresponding increase in the number of callers hanging up.

Knowing this in advance allows better planning and can have impacts beyond manpower plans - is it really a good idea to run a TV commercial that generates calls to the Call Center at a time of the day when you have fewest staff? You can experiment quickly and easily to find out how a marketing campaign will affect performance in the Call Center, and how sensitive your performance is to staff absence.

Try out our simple Call Center demo. It will run with a range of staff, and then produce performance graphs showing the non-linear trade-off between busy staff and high performance.

Features Used:

Call Center simulations normally make use of data tables for storing caller numbers, Label Routing to assign callers to skill specific Agent groups, and the Shelf Life feature in Storage Areas.

Top Tips

Shelf Life is a very powerful feature.

It can be used to allow items to move from a Storage Area when they have been in the Storage Area for more than a certain amount of time. This has uses in:

• Call Center simulation for simulating hang-ups after the caller has been on hold
• Healthcare for simulating patients occupying bed spaces, where beds are spaces in the storage area
• Queuing systems for simulating customer walk outs

Each item in a system can have a separate Shelf Life, so can be unique, with perhaps the value of the Shelf Life sampled from a distribution. This means that each work item can be assigned a different shelf life, and the behavior of individuals simulated more accurately.

How To.. Set up Shelf Life

Setting up Shelf Life is straightforward. Create a store, and type a number into the Shelf Life parameter. You will also need to create a "special" work center that pulls work items from the storage bin when they have reached their shelf life. Use the Expired Only setting in a Work Center, Routing In option.

To give each Work Item an individual Shelf Life:

Create a Label and assign a value to the label in the Work Entry Point. Assign the Label a value through the work Entry Point, based on a randomized distribution	Use the Label name in the Storage Area's Shelf Life parameter by double clicking on the Shelf Life entry field
And make sure a Work Center pulling form the Storage Area has Expired Only selected as its Routing In option.

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*SIMUL8 Corporation does not seek to recommend the purchase of any text, merely provides this link as an example of a simulation specific Call Center oriented text.