Preface: I am working in a company where most of the employees are in their early 20s. We have a very open culture and office. This is great to have a very friendly and low-stress working environment. As a byproduct, productivity is low and almost everyone is behaving fairly unprofessionally. They don't respect deadlines, juniors don't follow instructions carefully. And a grave lack of mutual respect among many colleagues etc.
As a member of management, what can I do to find a balance between a fun and free working environment, and utter chaos. I don't want to make any dramatic change that upsets staff. I am hoping to slowly instill some more discipline.
Question: At a high level, what management principles are there that I could employ to focus staff on being more task orientated rather than recreation?
Update after five months:
Further analysis revealed the root of some of the problems. Seniors were micromanaging and under-delegating, resulting in a lack of ownership among junior staff.
We slowly turned it around with increased transparency and empowered everyone in the team to make decisions on their own. In about three months time the difference was astonishing. Almost everyone takes ownership of their work. People seem more motivated, and better yet, I don't have to work on the weekends.
I will try to post another update few months down the line.
one year update
As some of the answers suggested, the problem was indeed with the lack of good management. We have come a long way since my last update. Simple things like following up deadlines, monitoring progress, addressing issues early, accountability, and appreciation create a huge difference. I let my team do whatever they what as long as the goals are met. There are few employees who always resist any change but they come around eventually.