As project managers, we have a lot of responsibility. We have to motivate and lead a team of people towards a common objective. We may not have direct authority over those people, so we have to find other ways of bringing them along with us. Trust helps. If project team members trust us, we find it easier to create and share plans, build budgets and deliver successfully. So what makes trust happen?
In The Power of Presence: Unlock Your Potential to Influence and Engage Others (Amacom, 2011), Kristi Hedges describes what she calls 'the trust equation'. Trust is a combination of credibility, reliability and intimacy, moderated by self-orientation. Let's take a look at each of these in turn.

trust equation

 

Credibility

Credibility is rational. It's not easy to measure, but it is easy to see. It is about our domain knowledge, so our ability to schedule projects accurately, manage risk, deal with issues and handle the project finances. Credibility is also shown through your credentials, so project management certifications like PMP or PRINCE2 can demonstrate your credibility at work. Credible project managers know how to present their points eloquently to stakeholders and the project sponsor. So much of credibility is tied up in the words you use and the impression you make on people when you are working with them.

Reliability

Reliability is demonstrated through your actions. Reliable project managers do what they say they are going to do. They deliver project reports when they are due. They turn up to meetings on time. They expect others to do the same.
You don't get to be known and trusted as a reliable project manager from just one action. You need to demonstrate reliability over time, so unfortunately you can't 'get' reliability from just one interaction with a project stakeholder. However, you can start building up their opinion of your reliability through making sure that you follow through on everything you say you are going to so.

Intimacy

Intimacy, says Hedges, is where emotion comes in to play. People like to work with (and trust) other people, so it is important that you are not seen as the robotic project manager at work. You can be fully credible and reliable, but if you don't come across as authentically 'you', people will find it difficult to relate to you and consequently difficult to trust you.
Part of generating this intimacy between you and colleagues is the ability to get others to open up. If they don't feel able to share their feelings with you, you may find it difficult to get to the heart of the issues on the project.

Self-orientation

Self-orientation is what moderates (or, in some cases, completely destroys) trust. It is the extent to which individuals put themselves first. If you opt to serve your own interests over that of your project team and stakeholders, you will find them turning their trust away from you.
For example, if, on a project, you choose to only do the tasks that serve to accumulate project management hours for the PMP application, and delegate everything else to another member of the team, then that would be quickly noted by your colleagues. To take another – equally contrived - example, if you don't pull your weight on a project or only do the minimum so that you can spend the rest of your time advancing your career through networking lunches, again people will quickly realise and this undermines any trust you may have built up between yourself and others. You get where I’m going with this.
You should aim to find a balance between ensuring your own interests are met (you don't want to be a doormat, after all) and making sure that the needs of other stakeholders are also met appropriately.