A batch of twelve pipeline clones was evaluated in the third phase of the Participatory Clone Evaluation programme in one of the estates in central Kerala. Vigorous and high yielding clones of the RRII 400 series were used as the check clones along with RRII 105. Girth of the clones recorded from the plots in the fifth year of planting and the average growth rate during the past five years was the basis for tappability projection of individual clones and the plantation as a whole. A variant approach has been taken from the prevailing and recommended approach, to the opening of a plantation for commercial crop harvest which is seventy per cent of the trees in a block or plantation attaining fifty centimeter girth, for tappability projection in the trial. The deviation has been the introduction of a fixed plot average of fifty centimeter girth in a block or plantation along with the reduction of required individual tree girth to forty-five centimeter instead of fifty centimeter while keeping the percentage of the population same as seventy per cent. Projection was made for each clone to calculate their tappability age under the prevailing recommended approach and under the proposed approach. Apart from proposing a variant approach, other probable factors affecting the tappability of the PCE trial have also been discussed. Suggestions have been propsed through the approach to improve the tappability of the blocks and the early tappability of the plantation of pipeline clones and also the early detection of promising and weak clones. Pipeline clones P 101 and P 104 showed high stability and less intra-clonal variability compared to the check clones of RRII 105, RRII 430 and RRII 417. Other promising pipeline clones in the trial were P 102 and P 110.