Team self-organization is one of the key principles  of Scrum and its introduction to an organization raises a number of interesting questions around decisions and decision making. Specifically, the introduction of Scrum leads to consensus-based decisions by the team. I believe that the consensus model of decision is superior the an authoritarian model and results in superior decisions and better information.
What does “Team self-organization” mean?
It generally means that the team is given the authority to make decisions on what to do and then to act on those decisions. In other words, it means that decisions are delegated down the corporate hierarchy and are made by the same people who do the work.
“It is solely and utterly the team’s responsibility to figure out what to do, and to do it.” -Ken Schwaber 
As an example, whereas I might have said to the team, “You need to use a Model-View-Controller (MVC) pattern to build the application,” I now need to leave that decision to the team. There may be a very real and valid reason why the team may consider another pattern.
This delegation of decision making can have unforeseen consequences in an organization. There are frequent concerns which are often expressed by the question: “How can teams be relied upon make the right decision?”
This question itself needs exploring. Firstly, what is meant by the “right” decision? When I, as an individual, say that a colleague made the “right” decision, what I’m saying is that, given similar circumstances, I would have made the same decision as they. When I ask, “How can we be sure that the team makes the right decision?” what I’m really saying is “How can I be sure that they make the same decision as I?”
Quite simply, I cannot.
While asking this question might give me some comfort, it is not a productive question for a number of reasons: It assumes that I have all the data that the teams has access to and that the team will collectively follow the same logical steps that I have. Both of these are unlikely, if not impossible.
Trust but verify.
If asking “How can I be sure that the team makes the right decision?” is not a productive question, then what is? I personally like the question: “Is the team adding value to the final product at the end of very sprint?”
“Trust but verify” -Ronald Reagan
Scrum requires a great deal of personal trust, but at the same time that trust must not be given blindly. I trust that the team will do their best and make the best possible decisions that they can with the information that they have. At the same time, I need to verify that the teams actions are congruent with the information they’ve given me.
I trust that the team is making the “right” decision, but I reserve the right to verify what they claim to be true.
Consensus decision making.
Not only does Scrum introduce a different view of the rightness or wrongness of decisions, it also impacts the decision making process itself.
Teams are typically consensus decision making environments. This is important because consensus decision making has characteristics that are different from authoritarian decision making.
“Consensus decision-making is a decision-making process that not only seeks the agreement of most participants, but also to resolve or mitigate the objections of the minority to achieve the most agreeable decision.” -wikipedia 
Detractors to consensus decision making often refer to it as groupthink. Although groupthinking can occur with teams, there are simple and effective ways to ensure that this doesn’t happen. Supporting an open environment where all points of view are given due consideration or appointing a Devils Advocate  are two such methods.
The strongest criticism of consensus decision making is that it’s inefficient.
Is consensus decision making inefficient?
Authoritarian decision making can be very rapid. In contrast, consensus decision making can take a substantial amount of time, especially if there are well informed but differing opinions. I have observed, however, that discussing the different positions increases the general understanding of the whole team resulting in higher quality decisions and better information.
But let us consider the question more closely. What is meant by “efficiency”? If by “efficiency”, we simply mean the time between making a decision and acting upon it, then I believe the answer is clearly “Yes, consensus decision making is more inefficient.”
If, however, by efficiency we mean “making well informed decisions based on a wider set of knowledge to best meet the current conditions,” then I believe that the team-based consensus approach is a far more efficient (and robust) model.
By introducing Scrum to an organization, principles of team self-organization are also introduced. The consequences of doing this are not always immediately obvious and will eventually impact not only how an organization makes decisions but also how those decisions are viewed and verified.
Given the opportunity to self-organize, a Scrum team will naturally trend towards consensus decision making, enabling them to make higher quality and better informed decisions.
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