Started a new job - how soon is too soon to make changes?

Are you their boss? If so, who cares when you make the changes? You are in charge. If you were hired to make changes, then make them. Just do them one at a time if you can.

Use the "snatch the bandaid off quickly" approach. It sounds as if you were hired to straighten things out and have the full authority to do so.

You've been gone longer than you were there. There are obviously a lot of problems that need to be addressed, but the real problems may not be what they seem to be at first blush.

I would take a measured approach to change. I would start with getting to know the concerns of the existing employees. Boss or not, if you want this to be successful, you need to have them onboard. And they have been there in the past six years, so they have some insight and knowledge you may not yet. It will also set you up with a better working relationship with them, which will make your department more successful in the long run.

Don't be a dictator off the bat. Be a collaborative leader. You will likely find you'll get better results.

Go for it. You work for the company, not for them. If they can't adapt, maybe it is time for them to move on.

THis^^^^

I always got more receptive responses if I had a staff meeting and asked for their input. A group effort in solving the problems with your guidance. When they feel you care about how they feel, change will be easier for them. Having a group discussion, maybe they will understand how or why things could work better another way. Of course there is always that one or two that dig their heels in and then you send them to change management classes. lol Congrats and good luck with your newish job.

It is not about how long to wait, but how to change. Talk with the staff, find out what works for THEM and why it works.  Part of me thinks the chaos may be hiding some embezzlement. But I also know when I've had someone come in and make changes without asking why things are done the way they are and the impact proposed changes have on my job it can raise a lot of resentment. Go at it from a collaborative aspect of making things work for everyone. 

I think how you go about it is important and would make a huge difference in how things are perceived.

I can be resistant to change. I have learned that through experiences with one of my current jobs. I am PT at that job. The agency started off very small (still is, but was just a few of us at first--me and the owner, and a few other very PT people that have come and gone). The owner is horrible with the administrative duties. Over the years she has apparently delegated those duties to others (once was the office manager and more recently she has hired a person who was an intern to help with this). Both times she failed to tell the rest of us that these other people had any authority to make changes in how things were done, so when they all of a sudden make these changes, it was not well received. Some of the changes made it very difficult for me to do the job in the capacity that I do (PT, while working another job) and changed things that may not have made sense for an outsider or for a larger agency with FT people working there. But the changes were completely tone deaf to WHY they were the way they were.

The most recent situation happened a few weeks ago. On reflection, I think if the owner had said, "Intern has experience managing businesses and I think she is a great asset to building the agency My goals are xyz. I am hiring her to help with x duties and look forward to your input in making these changes." This would have given me a chance to become used to the idea of change, think about what changes, if any, I see as necessary, etc (In this situation the intern did approach me to talk about what changes I would like to see, but I was so taken off guard by the whole conversation because I had no idea that she was in that position).

If people think that you are listening to them and have their best interest in mind (along with the company's), they will be more receptive to change.

This is the approach I would take as well.  Work with everyone’s skill set but if the dept is in recognizable chaos, procedures in place are not working and need to be revised. 

Good luck! 

Bolded is the answer.  They are the boss, not the staff.  If we waited around to do what everyone agreed on, it would never be done.
You don't have to be a jerk about it, changes can come with kindness.  If they don't like it, too bad so sad.  Otherwise, they will adapt (probably quickly), so they can keep their jobs.

There's a big difference between waiting for everyone to agree - which is neither viable nor desirable - and being sure you have the information you need (some of which will come from existing employees) to make the *right* changes. That takes some time. 

The bosses allowed things to get to the chaotic point it is today before they made a change. Of course they now want it fixed yesterday, but if they want it fixed properly, they need to allow a thorough process of discovery and gradual implementation. 

Asserting positional authority to make sweeping changes is rarely the answer. 

IME, if you go in assuming your solution is correct, you've already lost. You can't just be looking to confirm your bias. You have to genuinely gather information (from a variety of sources, including staff) and THEN make decisions. Otherwise, you are often solving the wrong problem(s).

Did you work with them previously?

IME, employees who like chaos use it to create a power base/fiefdom within the department and/or the illusion they are busier/more critical to the organization than they really are and/or embezeling could be at play. I'd look at the motivation of the employees to keep things the way they are. 

First full time week on the job is the time to get input from these employees as to what works and what doesn't, and what they see as solutions before you starting implementing changes.

Well I'm not a manager of staff but this sounds like brilliant advice!