If some of your collaborators do not want to exercise responsibilites right away, how can you find the motivations that could animate them?

It doesn’t make sense. One is employed to be useful and productive. Irrespective of personal circumstances especially during working time, assume your responsibility. Else go on leave.

Firstly, as a team leader, I must always lead by example. And they must have seen  it in me before this period that I do not toy with my responsibilities. In finding solution to this, effective communications should take place. I will let them know the consequences of trying to run away from responsibilities. Not only this, I will let them realize what is ahead of them in term of achievement if they carry out their responsibilities even without being told. I believe with all these, they would definitely be motivated and do their tasks.

First of all , the spirit of the team work must be developed 

sharing the the information between the team and must have effective plan " B"

I think that it is extremely important to get the buy-in from different individuals during a project or in the event of change.  Effective communication throughout the process will also benefit the outcome of said project.

It is also vital to have peers and subordinates to have faith in you as a colleague.  This will be achieved by being consistant, firm and fair and by getting input from peers and subordinates in order to determine the most effective method to achieve goals.

By establishing a sense of a "team", the team members should understand each of their roles within the team and will therefore understand exactly what is expected from them for the team to achieve it's goal.

I accompany them and help them in their efforts.

I reassure them that I am available to help them at all times

As a leader i need to become a good example to them by following the rules and regulations of the company and my responsibility. And from that they become motivated in doing their assigned tasks.

Ask to know reasons so we can understand the problem and fix it , each one has his mood who changes everyday depending on situations but the most important thing is to be comfortable and motivated at work so by asking we could find out  why the person refuses working  and then we hepl him to bring back his capacities .

WE NEED TO RAISE THEIR SPIRIT OF WORK. REMIND HIM THE RESPONSIBLITIES THEY HAVE AS A EMPLOYEE. 

We need to climb has this employee skills acquired for the position of responsibilities and we need to ensure that it is able to take over this responsibility.interpersonal communication is among the keys to motivation.the employee must feel safe within the company.

It is not some time possible that everyone follow your policies and responsibilties, in this cas we find find out the gaps to boost their motivation and if require, fulfill their desires.

This is completely normal, and i don't think anything otherwise. Finding motivation is linked with the mission on hand.

I don't get caught up in the "all or nothing" mindset.This doesn't have to be complicated.

Doing something is better than doing nothing.

Do what you can do consistently then worry about optimizing later as you gain traction. I always remember, getting started is everything.