You may have to look inside yourself before you look outside your firm!
1. The grass isn't always greener - speak to former colleagues who have already left your firm. How are they getting on ? What made them make the leap ? What have they learned from the experience ?
2. Culture - different firms clearly have different cultures. Make sure that you don't join a firm that's not a personal fit.
3. Does your potential move fit in with your long-term career plan ? It's no good making ad-hoc moves - you need to have a longer term strategy, and your next job should get you a step closer to your ultimate goal.
4. How secure are you likely to be in your new role ? How financially stable is your new firm ? Does the firm have a clear and prudent strategy ? Does it have a reputation as a 'hire-and-fire' outfit ?
5. Work / life balance - will you be prepared to put in longer work hours if your new role requires it, and how will this impact your life outside of work ?
6. How are you likely to get on with your new boss ? This individual will be pretty key to your success in your new role. Have you been able to find out from others how good / supportive a manager he / she is ?
7. What have you been able to find out about the attrition rates in your new team ? How come the current role is even open - was the incumbent promoted within the firm, or did he / she just move on as they were burned out / demotivated in the role ?
8. Will you miss your work colleagues ? Something that is often not considered - having a good relationship with fellow employees can take time to build, and can help when times are difficult. Are you really ready to start to build new work relationships ?
9. Finally, think carefully about what you are giving up - are you just going through a difficult period at your firm, and not focusing on the long-term opportunities that are there ?
Is it really you that needs to change to succeed - what's the point of changing firms if you don't have the right attitude / work ethic / ambition ? You may have to look inside yourself before you look outside your firm!