Hi,
With the additional inputs, my understanding is that you are seeking a format/program that can capture the achievements of your clients, which they can then present to current employers to leverage growth prospects or showcase the same to prospective employers.
As a prelude to this, it is imperative that they have a clear outline of their JD and KRA, for these would set the parameters to assess their performance and identify their specialized knowledge base and skill sets.
Ideally, your clients should be encouraged to record their major achievements as often as possible and review it, if possibly monthly or at least quarterly. For example, if you take the case of an officer in a bank, apart from their routine targets, the additional targets set could include their contribution to cross-selling the bank's products like insurance, garnering FD, and getting new clients/accounts. In effect, what this means is that the officer would, with each promotion, actually be handling larger and larger volumes of business which, when quantified, showcases his/her growth and reflects their abilities and strengths.
Recording the above is a very personalized and individualistic matter. What matters is being able to see the growth, the achievements, the learning, and understanding reasons for failures. Presenting these is also a matter of personal style and communication skills. For instance, a certain scientist when presenting his achievements told the management that in the first year, his target was to get an independent charge of a project which he managed before the year was out. In the second year, he had kept a target to ensure that in addition to meeting his own project deadlines, he aimed to ensure that his expertise was used by at least 6 out of the 17 projects that were ongoing. He managed to actively participate in 8 projects and additionally got another independent project to handle when the team lead left. He then outlined his targets for the next 5 years. From senior scientist, he was made an additional director simply because he showcased his abilities and performance and outlined his growth path.
I trust the above provides some roadmap and helps you guide your clients.
Regards