  Serious searches for the weakly interacting massive particle (WIMP) have now
begun. In this context, the most important questions that need to be addressed
are: "To what extent can we constrain the WIMP models in the future?" and "What
will then be the remaining unexplored regions in the WIMP parameter space for
each of these models?" In our quest to answer these questions, we classify WIMP
in terms of quantum number and study each case adopting minimality as a guiding
principle. As a first step, we study one of the simple cases of the minimal
composition in the well-tempered fermionic WIMP regime, namely the
singlet-doublets WIMP model. We consider all available constraints from direct
and indirect searches and also the predicted constraints coming from the near
future and the future experiments. We thus obtain the current status, the near
future prospects and the future prospects of this model in all its generality.
We find that in the future, this model will be constrained almost solely by the
future direct dark matter detection experiments (as compared to the weaker
indirect and collider constraints) and the cosmological (relic density)
constraints and will hence be gradually pushed to the corner of the
coannihilation region, if no WIMP signal is detected. Future lepton colliders
will then be useful in exploring this region not constrained by any other
experiments.
