Small-unit water purifiers for remote military outposts: A new application of multicriteria decision analysis

During the U.S. military's first 145 years, waterborne and other infectious diseases caused more casualties than battlefield injuries, underscoring the importance of clean drinking water to military success. Ensuring drinking water safety poses special challenges to the U.S. Army Special Operations Forces, because treatment equipment used in the conventional Army is too heavy and operationally complex to deploy to remote outposts. Due to the lack of purpose‐built water purifiers, Special Forces often rely on commercial‐off‐the‐shelf systems, but guidelines on selecting optimal systems for specific deployment contexts are lacking. To fill this gap, this research examines whether multicriteria decision analysis (MCDA) can provide an operational framework for selecting water purifiers for Special Forces. Our objectives are to apply MCDA to help an officer preparing for village stability operations in Afghanistan select a water purifier and to assess whether other Army stakeholders agree with the officer's choice. In addition, because previous research has suggested that alternative MCDA methods can yield different rankings of decision alternatives, we test whether the MCDA method used is as important as who conducts the ranking. Toward these objectives, we use 4 MCDA approaches for eliciting preferences among 4 water purifiers from the deploying officer and 6 other Army stakeholders. The results show that regardless of method, the officer and 5 of the 6 stakeholders identified the same preferred alternative, although rankings for the less preferred water purifiers varied by method (intermethod rank‐order correlation = .57). In responses to survey questions, stakeholders indicated that they would support using the results to support decisions about water purifier acquisition (average support = 5.3 on a 0–6 Likert scale with 6 indicating strongest support).