Modeling and debiasing resource saving judgments

Ola Svenson
Nichel Gonzalez

Svenson (2011) showed that choices of one of two alternative productivity increases to save production resources (e.g., man-months) were biased. Judgments of resource savings following a speed increase from a low production speed linewere underestimated and following an increase of a high production speed line overestimated. The objective formula for computing savings includes differences between inverse speeds and this is intuitively very problematic for most people.The purpose of the present studies was to explore ways of ameliorating or eliminating the bias. Study 1 was a control study asking participants to increase the production speed of one production line to save the same amount of production resources(man-months) as was saved by a speed increase in a reference line. The increases judged to match the reference alternatives showed the same bias as in the earlier research on choices. In Study 2 the same task and problems were used as in Study 1,but the participants were asked first to judge the resource saving of the reference alternative in a pair of alternatives before they proceeded to the matching task. This weakened the average bias only slightly. In Study 3, the participants were askedto judge the resources saved from each of two successive increases of the same single production line (other than those of the matching task) before they continued to the matching problems. In this way a participant could realize that a secondproduction speed increase from a higher speed (e.g., from 40 to 60 items /man-month) gives less resource savings than the same speed increase from a first lower speed (e.g., from 20 to 40 items/man-month. Following this, the judgments of thesame problems as in the other studies improved and the bias decreased significantly but it did not disappear. To be able to make optimal decisions about productivity increases, people need information about the bias and/or reformulations of theproblems.



Millions for research into maritime transport and the environment

Maritime transport is a major source of emissions of harmful air pollutants and carbon dioxide. In a new project, a research team from the Swedish National Road and Transport Research Institute (VTI) and the University of Gothenburg has received SEK 6.4...


New research programme for more efficient travel

The Swedish National Road and Transport Research Institute (VTI) is playing an important role in a major new research programme to find radical solutions leading to fewer trips and more efficient travel, along with tools to enable better use of roads and...


Simulator used to practice emergency responses safely

Emergency responses of the police, ambulance, and rescue services are associated with a high risk of accidents, but practicing them in real traffic is neither safe nor permissible. A simulator-based method developed by the Swedish National Road and Transport...


Simulation of cut-in by manually driven vehicles in platooning scenarios

A study in a VTI-driving simulator has showed that a platoon will be able to handle a cut in from a manually driven car. The results of this study have recently been presented at two conferences in Japan.



The five-year anniversary of European Road Profile Users' Group (ERPUG) Forum will take place at Ramboll head quarter, Copenhagen, Denmark October 19-20, 2017.


Self-driving buses in Sweden next year?

A self-driving, fossil-free bus. This idea might become reality through a forthcoming collaborative project involving the Swedish National Road and Transport Research Institute (VTI), Linköping University and several other participants. The project group aim...