The main legal point established in the judgment is the application of the principle that higher qualifications in the same faculty can be considered to presuppose the acquisition of lower qualifications, as well as the reliance on expert opinion in technical matters.

Thottathil B. Radhakrishnan, J.

Heard the learned counsel for the appellants in both the appeals and the learned counsel for the contesting respondents who are the petitioners in the writ petition from which these appeals arise.

2. W.A.No.1874 of 2012 is filed by two candidates included in the rank list which was challenged in the writ petition that led to the impugned judgment. They plead that they are adversely affected by the judgment impugned, though they were not parties to the writ petition. They have been granted leave to appeal against the judgment in the writ petition.

3. W.A.No.2193 of 2012 is by the Kerala Public Service Commission challenging the judgment in so far as the principles attempted to be settled through the impugned judgment are pleaded as erroneous.

4. The Public Service Commission notified vacancies for selection to the category of Operator in the Kerala Water Authority, hereinafter referred to as 'KWA'. The service in the KWA is governed by the provisions of the Kerala Public Health Engineering Service Rules in so far as State service categories are concerned and Kerala Public Health Engineering Subordinate Service Rules which relate to the subordinate service. Those rules have been adopted by the KWA.

5. The qualification prescribed for the post in question is as follows:

"(1) Pass in S.S.L.C Examination or equivalent qualification.

(2) National Trade Certificate in the Trade of Mechanic (Motor Vehicle/Electrician)"

The PSC notified the aforesaid qualification in its notification. In the selection process, it also considered candidates who had Diploma or Degree in some branches of Engineering. When the short list was prepared, a writ petition was filed challenging the action of PSC. After the publication of the rank list, the writ petition was amended, however without impleading all the selected candidates, in particular, those who have instituted W.A. No. 1874 of 2012. The learned single Judge concluded that Diploma or Degree cannot be treated as qualifications which are higher qualifications to the trade certificate which was prescribed and there was no way for the PSC to go by a principle of equivalence in bringing persons also within the field of choice. The writ petition was so ordered however directing that appointments already made would not be disturbed and that the declaration would affect the appointments to be made in future from the rank list.

6. At the outset, we may note that it is trite law that without impleading necessary parties to a writ petition, such a question could not have been decided, particularly, when rights of persons in W.A. No. 1874 of 2012 would stand abridged without being heard. The appellants in that case are included in the rank list. Their identity was certain. Their eligibility to be appointed was found by the PSC and they had therefore the vested right to be offered appointments from the rank list. So much so, the impugned judgment cannot, in any manner, affect their right to be appointed in terms of the rank list. The judgment impugned in W.A. No. 1874 of 2012 does not affect their such eligibility and the said judgment shall not be operated in any manner adverse to the interest of the appellants in W.A. No. 1874 of 2012. It is so ordered.

7. Onto the larger question raised by the PSC and the appellants in W.A. No. 1874 of 2012, vis-a-vis, the contentions of the writ petitioners who succeeded before the learned single Judge, we need to note that the different categories in subordinate service stand with prescribed qualifications of National Trade Certificate, Diploma and Degree. Coming to the State service, we see that the different categories under that service stand with qualifications of Diploma and Degree being prescribed. We also see a provision whereby, there is proportionate advancement by way of promotion or by transfer appointments from lower categories to higher categories until those in the subordinate service reach the State service. Taking into con