Companies often open positions up to external candidates because they are legally required to do so, or 'just in case' the ideal person shows up from outside, even though they already have a selection of internal candidates to choose from. This is particularly the case when an organization is restructuring, which seems to be very common at present. When you think about it, this leaning toward candidates they know is perfectly natural, even if you, as an external applicant find it frustrating.
Resumes and even cover letters are often written by others, and the company only has the interview to be sure that you are really the kind of person they want. Therefore, you need to try to establish enough rapport with the Personnel Manager for them to connect you with your application, and consider you seriously. How can you do this?
1. Without being obnoxious communicate with the Personnel Manager during the process. Although they are busy people, part of their job is to find the right person to fill a position, so if you believe you are qualified for the position it is quite acceptable to call and ask specific questions about the position and the field of candidates. This gives you more information, and also gives them an extra opportunity to get to know who you are. It is also a good opportunity to find out more about the organization than you can learn from their website and advertisement.
2. Express your interest in the position clearly in your application, and state that you hope they will call you for an interview. In an effort not to seem pushy, some applications sound indifferent. The Personnel Manager is more likely to call the enthusiastic qualified candidate in for an interview, than the one whose only clear expression of interest is that they bothered to present an application.
3. Demonstrate your interest in, and commitment to, the vision of the company in your cover letter. Let them know that you are keen to work with them, and give your reasons. Also try to show how you can contribute to their vision, and what unique perspective or skill you will bring to the organization.
4. Let them know that you are keen for them to contact your references. This demonstrates your confidence that your Referees will support the things you have said in your cover letter and resume about your personality and abilities.
When you are called for an interview be sure to prepare carefully by researching the organization, and thinking through specific reasons why you would like to work for them; studying the job description, and thinking through how you would approach the various aspects of it; and try to relax enough so that you can convey some personality during the interview. An internal candidate is at a real advantage at this point, because even if they do not do very well in the interview they are known within the company. You only have this one chance to make an exceptional impression. At the same time you have the advantage of not knowing about any internal issues the company may have, so you can honestly convey your enthusiasm without any negative overtones that an internal candidate may communicate.
The Personnel Committee is looking for the right person for the job, and it is your place to convince them that you are that person by demonstrating competence, enthusiasm, and commitment, if you can do this, you will be a strong candidate.