Predictive dialers

A predictive dialer is a computerized system that automatically dials batches of telephone numbers for connection to agents assigned to sales or other campaigns. Predictive dialers are widely used in call centers.
History :
While the basic autodialer merely automatically dials telephone numbers for call center agents who are idle or waiting for a call, the predictive dialer uses a variety of algorithms to predict both the availability of agents and called party answers, adjusting the calling process to the number of agents it anticipates (or predicts) will be available when the calls it places are expected to be answered. (The auto-dialer preceded the predictive dialer).

The predictive dialer monitors the answers to the calls it places, detecting how the calls it makes are answered. It discards unanswered calls, engaged numbers, disconnected lines, answers from fax machines, answering machines and similar automated services, and only connects calls answered by people to waiting sales representatives. Thus, it frees agents from listening to unanswered or unsuccessful calls.
Functioning :
The predictive dialer exhibits predictive behavior when it has more call attempts (dials) outstanding than it has agents that are already available to handle calls. The predictive dialing happens when the predictive dialer dials ahead of the agents becoming available or when the predictive dialer matches a forecast number of available agents with a forecast number of available called parties. The matching and dialing ahead perspectives provide the large increases in dial rates and agent productivity.

If a system has 100 agents working on it, the dialer will dial a number of calls sometimes crudely based on a phone line to agent ratio of 1.5:1 or 2:1. This means that for each available agent, the system will dial the phone numbers of two potential customers. As these calls are made to the telephone network the dialer will monitor each call and determine what the outcome of the call was. From 150 calls made, the system will immediately strip out any unproductive outcomes, such as busy calls (these are usually queued for automatic redial), no answers & invalid numbers. Some predictive dialers incorporate "answering machine detection", which tries to determine if a live person or answering machine picked up the phone. This is one cause of the typical delays that one may experience before being connected to an agent.

The advanced predictive dialer determines and uses many operating characteristics that it learns during the calling campaign. However, this level of performance may require a sufficiently large critical mass of agents. Conversely, it becomes increasingly difficult to maintain a high talk time percentage with a lower number of agents without increasing dropped calls.
Silent calls:

Predictive dialing systems use algorithms to control the ratio of calls to agents. Because a dialer cannot know what proportion of its calls will connect until it has made them, it will alter its dialing rate depending on how many connections it manages to achieve. Occasionally the system will get more live parties on call attempts than there are agents available take those calls. Consequently, the dialer will disconnect or delay distribution of calls that cannot be distributed to an agent. This is known as a silent call or a nuisance call. The called party hears only silence when the predictive dialer does not at least play a recorded message.
Types:
Predictive dialers perform the same function but the architecture and delivery methods can vary greatly between manufacturers. There are several types of predictive dialing.
1. Soft dialers
Software only solutions use ISDN messaging, or a CTI link to provide call progress analysis for calls made. Software only dialers are often cheaper because they do not require expensive telephony components, but in some cases can offer less functionality than more traditional 'hard dialer' solutions, particularly when it comes to detecting answering machines (AMD) and integration with other 'voice' related functions (voice recording, IVR, speech recognition, text-to-speech etc
2. Hard dialers
Hardware dialers use dedicated telephony switches to perform call progress analysis and answering machine detection. Those switches usually have two main types of connections, agent audio and external audio. The agent audio connections are usually simple T1/E1/ISDN etc. telephony spans which are connected directly to an existing PBX (although other connection types that do not require a PBX are available such as Analogue or VoIP connections). When an agent first logs in for the day, the dialer will place a call from the switch directly to the phone on the agent's desk.
3. Smart predictive dialers
Smart predictive dialers combine voice broadcasting with phone agents who are prepared to handle calls initiated by the dialer. Answering machines, busy signals, and no answer calls are processed in a manner similar to that of a normal predictive dialing system.
4. Hosted predictive dialers
Typically, the only requirement for a firm to use a hosted predictive dialer system is a computer with an Internet connection and a telephone line for each agent.

Hence A predictive dialer can dramatically increase the time an agent spends on communication rather than waiting: a 2002 survey indicated an increase in talk time from twenty minutes in the hour to almost fifty. The system is most suitable for low quality lists and large numbers of agents; a high contact rate can overwhelm the system.