We use 360 Degree Feedback, will definitely give low scores to the problematic senior
Don't do this.
(I want to be clear here that if you think they are committing fraud with regard to fake reporting of work done, or are going to tank an entire project, or something equally serious, then you do need to raise it to the appropriate channels, but it seems like your question comes from a dual "they don't work as hard as me" sour grapes combined with "I'm not fairly compensated or rewarded" sad feelings, rather than serious legal/moral problems, so that's where this answer comes from).
So yeah, don't do this.
Giving them low scores will:
- Not hurt them. They will not be demoted, they will not have their salary lowered. If it comes to a head, they will be listened to because they are senior.
- Not benefit you. You will not be promoted or have your workload decreased, or your salary increased, for complaining and giving low scores.
- Make you look bad, for being unable to get on with your team
- Make your team look bad, to the rest of the developer teams and to the wider company, for being divided, inefficient, and less productive.
Quoting a lot from here, but it's worth reading in full:
We technologists work harder, tend to bring more in terms of natural ability, and yet “they” (meaning executives) make three or ten or fifty times as much, for considerably less work, and they have a lot more job and career security. We learn new programming languages and tools (as our jobs, constantly evolving, require) on our own time, and sometimes sacrifice weekends to tackle production issues. They, on the other hand, can work 11-to-4, because their bosses care more about in-group cohesion than what gets done.
They define their jobs and, unless their assertions are utterly unreasonable, write their own performance reviews, easily justifying raises.
Why are “they” winning? It’s a lesson in collective intelligence. It really matters. [..] Often, we use our individual gifts to compete, stupidly, with each other. We need to stop being resentful of “business types”, and start learning from their superior collective intelligence. What are they doing that we aren’t? We’re working harder and we are smarter, individually speaking, but they are working smarter, which is what actually matters.
[..] Can you even imagine a Harvard MBA justifying his own working time in terms of two-week “sprints” or “iterations”? Of course not. It’s inconceivable. So what did they do right that we did wrong?
[..] A friend of mine worked at a large bank with “360-degree” performance reviews. Ratings were on a 9-point scale with 5 as the intended average. The lowest-rated group was technology, where the average person got about a 6.5. The salespeople and executives and business analysts all gave each other high ratings, regardless of whether they thought each other “deserved” high scores, and so all of the “soft skills” departments came in with averages above 8.5. The programmers gave each other “honest” ratings, which shows collective stupidity, because it showed a willingness to rat each other out to management. The business people had the collective and political intelligence not to put bad scores, even when they were deserved, on the record. In most of the bank, people wrote reviews for themselves and had them signed by peers. There was a mutually beneficial (i.e. positive-sum) trade of credibility going on. Business people are smart enough to give criticism verbally, off the record, and to give glowing reviews when on the record. They recognize that preserving the credibility of the group is one of the most important things that they can do at work. Not so for programmers.
I can imagine that some programmers will read this and say that it proves that we are the honest ones, and that “business people” are corrupt in some way. I disagree completely with that viewpoint. They played politics effectively, and the programmers didn’t. End of story. The business people (traders, investment bankers, salespeople) saw that the executives were trying to collect data that could be used against them, and so they jammed the signal in order to minimize the probability of harm coming to anyone. The programmers played politics poorly, because they couldn’t keep their mouths shut, and probably got hit harder in the next round of layoffs.
[..] Programmers are “honest” when it comes to reviewing each others’ performance (which is not to say that they’re correct) and it tends to have three effects. One is that it creates drama. The business people realized that if everyone got top ratings and glowing verbal feedback, the performance-review system could be rendered a formality and they could all get back to work. Problem solved: it becomes a once-a-year annoyance that takes up half an afternoon, rather than something that people fret and grouse about for months beforehand and afterward. The programmers, by being stupid and back-stabby, gave the performance reviews teeth, and created drama that lasted for a long time. The second is that it creates division. Numerical performance scores lead to false objectivity and that leads to permanent rifts within the company, as people withhold information and form alliances in order to game the system. Thirdly, it makes programmers look incompetent. If they’re getting the lowest ratings (because they’re slamming their peers, reports, and bosses) then the organization concludes that must be the worst people in the firm. They’ll never get respect.
Is your team more likely to get rewards, pay rises and promotions, if everyone gives each other bitchy and 'honest' 360-degree feedback, or if everyone on your team sings each other's praises?
Your number one concern is whether you have enough work, whether you can do it, and whether you feel compensated fairly. This is between you and your employer. What other people do, what they earn, what they get, is not your business unless they are your employees to manage. Seeking to reduce their situation is lame, instead seek to improve your situation.
Your number two concern is keeping everything working well. Make your team look good. To other teams, to other parts of the company. Not by being a doormat, or by doing their jobs for them, but by appearing publically supportive - they are your teammates, your coworkers. Team success is your success, even if they take most of the credit. Angle to get more of the credit for your team and more for you as well, if you need that to feel valued.
Reduce your "doing 80% of the team's work" output, if you need to. Are you paid like 80% of the team? No. Do you get a share in the rewards of the product sales? Probably not. Are you "working hard" or are you "working more than you're paid for, then being bitter at other people who are not"?
You say you can't ask for more money and can't get promoted, but feel you are working more than you are paid for. There's only one thing that can change here to correct this triangle.
Report what great successes you have, to your managers, make sure they know you are working, and make sure they know you know it. Sing your own praises, let others manage themselves. But sing their praises as well, so they'll do the same for you. Seniors singing your praises would probably have more influence than you think it ought.
Related: The IT Crowd sitcom, 'team' scene