Overview
I'm a scrum master and also manager of an average team and honestly its my first time I'm responsible to manage a group of developers more than 10 people(around 12). So maybe my question seems unclear or misunderstood by some of you but please be patient with me as I want to learn from you guys as its my first experience. Also please share any resources you think can be useful.
When I managed some small teams in the past years, I never encounter such problems, but it seems when number of team members grow, the management is significantly harder.
Problem
The problem begin when I first came into the team (its almost 10 days) and from the first day I realized some of our veteran employee's velocity is lower than expected, work output is not on time and in overall some times we are missing deadlines. I just tried to monitor everyone's daily work performance and realized that some of them don't have enough engagement with the work (like they are working with their cell phone, surfing social medias, dont care about deadlines and trying to escape the office as soon as possible) and as I don't have any defined standards anywhere I can't act properly. I don't want to go around and talk to each one about this or bullying and start banning all cell phones / social networks. I think these approach won't be effective at all.
I really and truly appriciate everyone's effort and I'm not saying they are too bad, but I truly expect more...
Goal
My goal is to increase employees engagement during work such that everyone of them feels the sense of ownership of the company and start to caring about deadlines, focusing on doing tasks and have more engagement when they feel company is in trouble and need their help as a team. Another goal is to help them avoid disturbing activities during work. My ultimate goal is to achieve better results and I realized its because team is not completely focus on the tasks because of mentioned reasons.
Question
I want to know what is your way/suggestion for me to increase employees engagement during work in such situtation. Do you suggest to ban working with phones and social medias to help employees focus on their actual tasks OR I should focus on encouraging everyone to work better and increase engagement by preparing some events/trips OR increase their salaries (however they are getting more than country's average salary regarding their position and I don't think it will be effective) OR start talking with each one of them and asking about what can I do for them to increase their engagement OR any other idea? I just don't want to be a pain in somewhere! And don't want to poorly react with the situation. I have to get the things on schedule and It will be counted as my first reaction/decision in team.
More info
Note that we are doing scrum, we have daily meetings, log all works and our PM tool is Jira and using Confluence as our knowledge management.
My question is specifically about "improving engagement in a software company". Specially when the company is in a critical situation.