Coaching
In decision-making, unrecognized assumptions and unacknowledged blinders usually pose the greatest threats to the quality of a decision. A coach will certainly bring suggested tools and techniques to the table to improve the decision process but one of the biggest values is to make team members aware of the unexamined assumptions, the cognitive biases, and the logical fallacies which are common in all decision processes.
For example, the absence of time is one of the biggest constraints on quality decision-making. People develop a number of ways of thinking to tackle major and minor problems in a tactical or strategic fashion (see matrix below). Each cognitive technique is useful in its context, indeed necessary. The challenge is to use each technique or combination of techniques only in the circumstances where it is appropriate. The coach is there to strike that balance between the familiar technique and the appropriate technique.
Circumstance
A complex decision has to be made and you are using a formal or informal approach involving other parties. You serve as the lead yourself or you have a team leader whom you trust to effect a robustly reasoned decision. However, given the complexity of the issue and the number of parties involved, there is always a risk of tunnel vision occurring, focusing on the hot topics while omitting key steps in the process or simply not prioritizing certain actions to the degree warranted. Having an independent party on-call for review and coaching is a flexible, cheap means of keeping the decision-making in-house but obtaining the quality arising from specialized knowledge and experience.
Activities
Review key steps in effective decision-making and map those steps to your own process. Suggestions provided on decision-making tools, approaches, team membership, etc. One-on-one training on any key decision-making tools or processes as required. Periodic review sessions structured over the life of the project.
Outcome
Timeline of team decision-making and key process check-points. Training. Improved familiarity and experience with structured decision-making.