© British Telecommunications plc 2001 Dynamic Scheduling in Mobile Workforce Management Ralf Keuthen PLANET Information Day, Ulm, 2003

© British Telecommunications plc 2001 Contents  Automated Mobile Workforce Management  The Workforce Scheduling Problem  TASKFORCE System Overview  Issues  Current/Future Work

© British Telecommunications plc 2001 Mobile Workforce Management  a.p.solve -- A Short History è Involved in mobile workforce management since è Produced two major Work Management Systems which have evolved into the TASKFORCE products we currently market. è a.p.solve (100+ employees) was spun out via the British Telecom’s Brightstar business incubator initiative in April è a.p.solve’s planning and scheduling products primarily support the management of mobile workers via Personal Digital Assistants and mobile telephony.

© British Telecommunications plc 2001 Scope  Large telecommunication, cable, utility and fix & repair companies typically maintain a fieldforce of 100s - 10,000s of technicians  The fieldforce supplies provision of service, repair and maintenance tasks on a daily basis (between 1000s - 100,000s of tasks/day)  Customers è Residential, Business (provision, repair) è Company itself (maintenance, repair)

© British Telecommunications plc 2001 Example: Mobile Workforce at British Telecom BT Customer Access:  a.p.solve’s TASKFORCE products currently schedule BT’s workforce of Service Technicians.  ~25,000 field technicians  ~150,000 tasks every day across the United Kingdom.  A high quality service at low operational cost needs to be delivered.

© British Telecommunications plc 2001 Work Management Organisation  Domains: Geographical partition of the work area into autonomous domains  Domains controlled by automated work management system  Supervised by a human controller

© British Telecommunications plc 2001 Organisation: How it works Call Centre Network Service TASKFORCE Handheld terminal Laptop Mobile Customer Service Work allocation and visualisation Dispatch work to technicians

© British Telecommunications plc 2001 Organisation: How it works  Customer Service: è take customer calls è arrange appointments  TASKFORCE: è provide customer service with a selection of appointment slots è Allocate work to technicians è dispatch work to technicians  Technicians è receive work details è travel to and carry out work è report back when work is finished

© British Telecommunications plc 2001 Workforce Management: From a Scheduling Point of View

© British Telecommunications plc 2001 Scheduling Model  Resources: è Technicians è Vehicles and other equipment  Activities: è provision, repair and maintenance work  Constraints: è time windows, access restrictions è precedence constraints è co-op, assists, etc.

© British Telecommunications plc 2001 Main Objectives Right man - right time - right place - right costs  Maximise productivity è number of tasks scheduled è most efficient resource for each task  Ensure a high quality of service è compliance with agreed appointments & due dates è work importance  - Minimise costs è travel times è waiting/idle times è overtime

© British Telecommunications plc 2001 Other Objectives  Workforce satisfaction è task preferences è preferred working areas  Business rules è every technician gets a job è avoid the splitting of tasks over breaks (if possible)  Avoid disturbances è robust schedules è flexible schedule Some of these contradict one another

© British Telecommunications plc 2001 Issues  Dynamics/Uncertainties/Complexities of problem  Scale  The need for a totally automated, online, system.

© British Telecommunications plc 2001 Dynamics  Tasks The company and its customers can è request è cancel è amend tasks (at all time!!)  Resources Availability subject to last minute changes è personal absence, sick leave, etc è changes to task completion times è vehicle breakdown

© British Telecommunications plc 2001 Uncertainties  Duration of tasks Uncertain due to è exact scale of work often unknown before a technician arrives on site è varying technician skill levels  Travel times Uncertain due to è weather è traffic conditions  Business objectives Resource manager can change business objectives

© British Telecommunications plc 2001 Complexities  Complex mixture of tasks: è different execution target times (appointment/commitments) è different task priorities: low - high priority tasks è Wide range in the duration of tasks: 8 mins - several days  Inter task dependencies can be complex è coops, assists tasks è pre-installation tasks è stock point visits, etc  Site access restrictions è security access è business opening times è road closure, etc

© British Telecommunications plc 2001 Complexities  Geographical complexities è diverse (London vs East Wales, etc) è Preferred working areas  Skills è heterogeneous workforce è diverse skill set  Work type and work skill imbalances è some geographical areas can be under resourced è certain skills can be under resourced  Business Rules

© British Telecommunications plc 2001 Scale Scale of individual problems domain dependent  Technicians: è 10s to 100s of technicians  Tasks: è 100s to 1000s of tasks Scheduler needs to cope efficiently with all domains

© British Telecommunications plc 2001 Issues  No realistic forecasting possible!  Assumed ‘static’ environment? è Optimised schedules quickly become sub optimal or even infeasible è What is optimality in an dynamic environment?  First thing in the morning everything changes !! (sick leave, new tasks, etc)  Building robust/flexible schedules? è Limited applicability è Radical changes to the current schedule may be desired

© British Telecommunications plc 2001 Scheduling Opportunities: Impact of Personal Digital Assistants on Scheduling Practice:  Mobile phones, laptops, handheld terminals, the Internet, etc è allows to dispatch tasks to mobile workers in real time è tasks are (usually) dispatched one by one  Scheduling impact: è allows to adjust the schedule to the changed environment è allows to correct (some) scheduling decisions made earlier However, the time available to react to changes is very limited

© British Telecommunications plc 2001 Available Tools:  Identify processing bottlenecks  Exploit scheduling opportunities  Maintain schedule stability and existing process plans.  Refine solutions.  Repair constraint violations.  Summarise solution states for human controllers and software agents.  Dispatch scheduling tasks to field technicians with respect to current schedule state and customer demand.

© British Telecommunications plc 2001 TASKFORCE System Overview

© British Telecommunications plc 2001 Needed Automation  Automated data flow from order source systems to job dispatch.  Schedule revision must be automatic and robust.  On line Dispatcher must be able to cope with corrupted schedules.  The real-line monitoring of the location of mobile technicians and their expected completion times is important.

© British Telecommunications plc 2001 TASKFORCE Developed by BT and employed since TASKFORCE supports:  Resource Management  Operations Management  Schedule/Jeopardy Management  Progress Management  Scheduling & Dispatching

© British Telecommunications plc 2001 System Overview

© British Telecommunications plc 2001 Schedule Manager  Planer that transforms customer orders (service requests) into scheduling variables with their associated constraints  Identifies tasks in jeopardy of becoming tardy  Pre-processes tasks & resource information according to business rules  Calls scheduling tools to create/maintain executable schedule

© British Telecommunications plc 2001 Scheduling Needs  Batch Scheduling  Schedule revision  Appointment booking support  Interrupt Scheduling  Route Optimisation  Schedule Dispatcher  What-If Scheduling  Schedule Visualisation & Manual scheduling support

© British Telecommunications plc 2001 Architecture Overview Visualiser DS Pre-scheduler Optimiser Interrupt Scheduler Dispatcher Intelligent Appointer Schedule Manager

© British Telecommunications plc 2001 Batch Scheduler  Runs overnight to construct high quality schedule for the following day è Build provisional start-of-day schedule è Schedule construction & route optimisation  Techniques: è Chronological backtracking based Constructive Algorithm  assign important and hard to schedule tasks è Local Search based optimisation supported by a constraint net to ensure feasibility  Stochastic Local Search: Simulated Annealing

© British Telecommunications plc 2001 Dynamic Scheduler  Run while schedule is being executed to maintain a high quality schedule  Responsibilities: è Absorb schedule changes and most up to date information è Rebuild, repair, update & re-optimise provisional schedule  How it works: è Perform frequent short batch runs to rebuild a feasible schedule è Pass provisional schedule to Schedule Manager

© British Telecommunications plc 2001 Dynamic Scheduler  Pre-scheduling: è Reload and try to rebuild old schedule  Tree Search assigning remaining important and hard to schedule tasks  Optimisation: è Low Temperature Simulated Annealing. Currently looking into more focused techniques such as exploring large neighbourhoods based on an ejection chain model, Guided Local Search, etc

© British Telecommunications plc 2001 Intelligent Appointer  Controller/call centre support tool  Heuristic based è find a set of feasible appointment slots based on the current schedule è suggest feasible appointment slots to human controller è controller books appointment slot and associates time windows with the new task è task is sent to schedule manager

© British Telecommunications plc 2001 Interrupt Scheduler Automatic Schedule Revision:  Reallocation algorithm to support situations where important work would otherwise fail. è The system can’t find an available resource for high priority work at specified times è Interrupt scheduler identifies a sequence of reallocations to free a technician to perform the work

© British Telecommunications plc 2001 Automatic Dispatcher  Online and event triggered System  Responds to requests for work from field force in real-time, making alterations to the planned tour as required.  Supports the management of uncertainties & last second changes to the schedule associated with: è travel time & task duration è arrival of new high priority work and cancellation of already scheduled work

© British Telecommunications plc 2001 Dispatching Algorithms  Rule based system. è If Field Technician request work then the Dispatcher identifies a task for the technician to service.  Rule Examples: è Find work on site for technicians rather than travel to new locations è Give preference to tasks getting close to their deadlines è Keep technicians from travelling outside their preferred working area è etc, etc This may result in the need to repair a damaged schedule

© British Telecommunications plc 2001 What-if and Manual Scheduling  Are off-line schedulers that support work controllers by providing the visual and analysis tools to try out different scheduling parameters and allocations to discover improvement opportunities without risk.  Changes to scheduling parameters can be applied to current or archived data and the resulting schedule can be examined in an off- line environment.  Changes can then be applied to live sites.

© British Telecommunications plc 2001 Schedule Visualisation Tools Compress schedule information and represent it in a way that can easily be captured by the user  Provides the human controller with: è statistics è tour task tables è Gantt chart è map tour representation

© British Telecommunications plc 2001 Schedule Visualisation: Gantt Chart

© British Telecommunications plc 2001 Schedule Visualisation: Map

© British Telecommunications plc 2001 Current/Future Work

© British Telecommunications plc 2001 Dynamic Work Crew Scheduling Field force activities can often not be carried out by a single person but need multi-skilled crews è safety reasons (gas, electric, etc.) è activity reasons (heavy equipment, etc.) è specific equipment (elevator unit, crane, etc) Examples:  Expansion/repair of the telephone network  Electricity/gas/water supply to new build homes  etc.

© British Telecommunications plc 2001 Dynamic Work Crew Scheduling  Workpackages instead of single tasks  Complex workpackages è long tasks (2h to a few weeks) è many inter task dependencies è different configurations possible  Skill matching è is a crew skill the sum of its crew member skills?  Task duration è If 2 people need 1 hour do 4 people need only 1/2 hour?  How and when to build, amend or break crews in a dynamic environment?

Intelligent End-to-End Fieldforce Automation