There’s something called "The Peter Principle" which says that at some point, every person rises to his or her own level of incompetence. For example, an employee is competent at her current position, but when given additional responsibilities or a promotion she’s not ready for, she ends up performing less than expected. It’s more like biting more than you can chew, and it’s something to watch out for.
Due to your efficiency, your bosses may see you as someone very reliable, or someone who can help them solve problems that they don’t have time to fix. While the amount of trust they give you can admittedly be flattering, you still need to know how to manage their expectations, and when they give you more work you can handle, you’ll need to say “no”—politely of course.
Here’s how to handle such situations without looking like you're skirting your responsibilities:
Assess your current situation.
Every person would like to be seen as a team player, which makes it hard to decline additional work; however, you need consider where you currently stand. How many projects are you handling? Are your tasks for the day done? How many reports have you managed to finish? Taking a look at your checklist can actually give your manager a fighting chance to get you on board, and at the same time, make you feel less guilty when you really need to say no.
Be honest about why you can’t accept additional workload.
There’s really no shame in telling the truth—that you’re too busy and you already have too much on your plate. In fact, your boss will actually appreciate it, because you’re not sacrificing your efficiency by accepting a job you can’t give your 100 percent to. At least you’re not wasting each other’s time.
While having someone approach you when you’re obviously very busy can be irritating, it’s important to temper your annoyance with empathy. The person asking you to take on more work may be swamped herself, and some time in the future, you might need that person’s help, too. Be neutral and firm with your reply, and don’t forget to be kind.
Suggest another solution.
When your senior has a request that you can’t accommodate, try to suggest another solution instead. Maybe give tips on who to approach, or give a work-around to the current dilemma. You don’t always need to always be the tagasalo, but you can still contribute in your small way.
Offer some other way you can assist.
Saying no to more work doesn’t meant that you’ll stop being helpful. Ask if there’s any other way you can make things easier that’s within the scope of your job: baka puwedeng makisabay sa email, or maybe you can ask the person you’ve already been dealing with to process your boss’ query. It can still be a win-win situation for the both of you, and you don't even have to stretch yourself too thin to do it.