Multi-Criteria Optimization

The operation including fault clearance and maintenance of supply networks is resource intensive and accounts for a substantial part of the cost for a network operator.

Costs can be reduced on different levels. For operational execution of scheduled maintenance measures as well as fault clearance, the efficiency can be increased in particular by reduction of non-productive times. Non-productive times include driving times to sites, setup  times, and documentation times as well as misrouted drives due to wrong information or qualifications.

Often systems for routing optimization are used for cost reduction in maintenance and fault clearance. However, due to the complexity of the operational requirements, the organizational constraints, and the mutual dependencies of the different activities in topologically connected supply networks, single-criteria optimization does not achieve the potential cost savings.

Instead, multiple operational objectives must be considered simultaneously and ordered by changeable priorities.

The following operational objectives (O) may apply:

  • Balanced and high utilization of the service staff (O1)
  • Appropriate resource assignments (O2)
  • Short driving times (O3)
  • Combination of similar tasks in adjacent locations (O4)
  • Keeping scheduled appointments (O5)
  • Etc.

These objectives can be further detailed by optimization criteria (C) such as:

  • Even and high utilization of service staff:

    • Minimization of utilization differences (C1-1)
    • Maximization of utilization (C1-2)

  • Appropriate resource assignment:

    • Determine minimum qualification profile (C2-1)
    • Minimization of external services (C2-2)
    • Maximum variety of jobs (C2-3).

In general, the optimization criteria cannot be fulfilled simultaneously and to the same degree since they partially contradict each other. The fact is displayed in the effect matrix (see figure).

The effect matrix shows that criteria can be synergetic or also compete with each other. Only the optimál balance of the criteria results in actual operational benefits.

Ignoring one or more optimization criteria can provide results which are unusable for actual operations. The consequences are costly manual reassignments of jobs and staff, increase of non-productive times due to misrouting, and additional communication overhead to clarify situations.

Algorithms which cannot appropriately perform optimization based on multiple criteria actually increase the operational costs which in turn are further increased by frustration and rejection by the involved staff.

It has been proven that the human brain is not capable of making optimal decisions based on more than five criteria. PSIcommand and the integrated Qualicision module provide optimization based on any desired number of criteria. Qualicision is a software for multi-criteria decision making. It is capable of achieving the operational objectives by intelligent determination and analysis of the current situation and balancing the objective and criteria conflicts.

Qualicision is fully integrated in PSIcommand via powerful internal interfaces. The full integration and the uníversal configurability of Qualicision enable easy and comprehensive configuration of criteria and constraints instead of cost-intensive programming.

Qualicision is already successfully used in a variety of applications in different industries. The expertise from these applications is bundled into ongoing technology transfer to enhance the optimization of workforce management.