The four factors of a successful team

Chapter six discusses why companies are starting to move away from using teams. To summarize the reason is that companies feel that teams take too much time to make a decision and team members shield themselves from responsibility. The book specifies four factors that should lead to a successful team, but if they aren't within the group, the group may fail.
The first factor is that the team is only as good as their weakest link. In order for a team to be good, all members should be top performers. This allows the team to have the skills to succeed.
The second factor is that the team must be trained in working as a group. This includes that they must know how to make group decisions and communicate. In order for group members to be on the same page, they must know how to talk with one another.
The third factor is that a company must assign the team with the right tasks. Small tasks, given to a team, are a waste of time and money. A company should assign the team with a challenging outcome that impacts others.
The fourth factor is that the team members must understand that some members will contribute more than others, it all just depends on the task at hand and the person's expertise.