AWASAutomated Work Assignment System

A Real World NP-Complete Problem

Huy Truong – COT 6410November 4, 2008

What is AWAS?

AWAS is a workforce-management system developed by GTE Service Corporation (now Verizon) in the early 1990s.

AWAS assigns jobs to field service technicians, allows technicians to report job status, completes work orders that flow directly into the billing system.

AWAS is being used by two of the largest telecommunication corporations in North America: Verizon and Telus (Canada)

I was a software developer on the AWAS program in 1998 at GTE Data Services in Tampa, FL

AWAS – High Level Architecture

Customer Relationship

Management (CRM)

Automated Work Assignment System (AWAS)A

dd Job

Provide

ET

A

Call

Input Data

Compute an Optimized Job Assignment

People Management

Software

Available Technician, Skill Level

Assign Jobs

Provide S

tatus

Billing System

Provide B

illing Data

Technician Performance Feedback

Bill Customer

AWAS – An Optimization Problem

Given: Set of jobs with estimated labor hours, required

skills, and location (customer location) Number of available technicians with skills Cost to travel between all customer locations

Question: What is the most cost effective way to assign

jobs to technicians?

AWAS – Converted to a Decision Problem

Given: Set of jobs with estimated labor hours, required

skills, and location (customer location) Number of available technicians with skills Cost to travel between all customer locations Number of hours, k, that jobs must be

completedQuestion:

Can we schedule jobs to technicians so that all jobs will be complete in k hours?

AWAS – Create A Math Model

Given: Set of pre-defined skills S = {s1, s2, s3, … sn}

Set of locations L = {l1, l2, … lm}

Set of jobs J = {(sj, lj, hrs), (sk, lk, hrs)… (sv, lv, hrs)}

Set of technicians T = {(si, sj, sm), (sv, sk), (si)}

Set of travel cost C = {(l1, l2, cost), (l1, l3, cost)… (lm-1, lm, cost)}

A positive number k

Question: Can we schedule jobs, J, to technicians, T, so that all

jobs will be complete in k hours?

AWAS – is a NP Problem

1. The AWAS problem is a decision problem

2. There is a yes instance verifier in polynomial time once the oracle provides the job assignments

Therefore, AWAS decision problem is belong NP

AWAS – is a NP-Complete Problem

Let’s consider the Multiprocessor ProblemGiven:

Set of tasks T = {t1, t2, … tn}

Set of processors P = {p1, p2, … pm}

And an positive integer t

Question: Can we schedule T so that all processors P will

stop by some time t?

AWAS – is a NP-Complete Problem

Let’s Create an instance of AWAS decision problem Given:

Set of pre-defined skills S = {s1} – one skill

Set of locations L = {l1} – one location

Set of jobs J = {(s1, l1, t1), (s1, l1, t2)… (s1, l1, tn)}

Set of technicians T = {(s1), (s1),… (s1)} – All technician has the

same skill. Number of technician is equal to number of Processors

Set of travel cost C = {(l1, l1, 0)} – a single zero cost to travel from location 1 to location 1

A positive number kt Question:

Can we schedule jobs, J, to technicians, T, so that all jobs will be complete in k hours?

AWAS - is a NP-Complete Problem

Multiprocessor Scheduling is a restricted version of AWAS decision problem. Therefore, prove by restriction that: All yes instances of AWAS decision problem

would be yes instances of Multiprocessor Scheduling problem and vice versa

Therefore, AWAS decision problem is a NP-Complete problem

AWAS - Interesting Facts AWAS also considers to assign the similar jobs

to the same technician. This improves productivity since the technician works on the same problem all day

AWAS handles jobs that need more than one technician

AWAS reassigns jobs through out the day to react to cancellation & new jobs

The original AWAS was written in C Verizon IT Solution promotes and sells AWAS to

telecommunication companies around the Globehttp://www22.verizon.com/it/products-services/telecom-software-applications/workforce-management/awas-index.html

AWAS - Interesting Facts

There are hate websites for AWAS since it “controls”, tracks, and maximizes field technicians productivities. “Can you sit around and let this system control

your lives, or are you going to stand up and fight against the new world order? Fear not, for we are here to protect you.”

http://www.hackcanada.com/canadian/phreaking/awas-guide.html

AWAS - Questions