Timing is everything in politics, stand-up comedy and wage negotiation (these three activities are pretty closely related when you think about it). Clearly, when a firm is under pressure, either to meet a big order, to fend off either a takeover or persistent criticism from investors, it may not be wise to bring up the subject of your pay. If there has just been an annual pay negotiation that has left you feeling undervalued, you might try and bring the matter up with your manager, but be prepared to be told that pay has just been settled for another twelve months. So with employers where pay negotiations are formalised on an annual basis, you may need to start building your case six months or so beforehand, to make sure managers are aware of your specific claim.
Of course, if the firm has just had a big success, and particularly if you have played a crucial part in that success, you have a much better chance of getting a hearing. But even here, be ready with the evidence of good work and why you are being undervalued, to avoid being seen as someone merely jumping on the bandwagon and cashing in on other people's efforts.
