People cannot be fully accountable. Full accountability is an unrealistic expectation. That's setting the bar too high. There are many reasons why people cannot be fully accountable: they do not have 100% control over themselves; willpower has its good days and its bad days; they cannot exert perfect influence on other people; other people have minds of their own; multi-tasking is a distraction that takes focus off specific-task accountability...and many other reasons.

So...

Some of the people can be accountable some of the time.

None of the people can be accountable all of the time.

People can, however, be fully accountable for a few certain actions within their control. They can Influence their own actions...not all their actions all the time, but definitely a few of their actions some of the time.

One key to success is matching accountability with those actions people can self-Influence and perform with skill, repeatedly.

Consider each person whom you want to be accountable.

What specific actions do they believe they can be accountable for? Those are the things to focus on. Those are the right baby steps to take. Those are the actions that will bring constructive change.

Note to Leaders:

Unless you know you know what people can be accountable for, don't assume. Don't ever assume. Put another way, avoid the temptation to pick specific actions you believe or expect others can be accountable for. Instead, encourage others to help you understand what they believe they can be accountable for. 

• Most likely they will pick items they know they can control or, at least, they think they have a good chance to control.
• Most likely they will pick items that align with their Talents, Knowledge, Skills, and Strengths...i.e., they will Take Talent To Task.
• Most likely they will pick items that align with their ability to exert self-Influence.