A method for decision making process, the method comprising: a) framing a decision problem comprising a drilling location for an exploration, appraisal, development, or pilot well in a subsurface reservoir; b) uploading existing frame data, including permeability and porosity data, relating to the subsurface reservoir into a reservoir modeling program; c) generating and combining at least 2 realizations of said existing frame data to create an ensemble of reservoir model (E 0 ), wherein said ensemble of reservoir model defines an input uncertainty band; d) deriving at least one system performance output variable and one or more target percentiles of said system performance output variable from an ensemble prediction of the ensemble of reservoir model model; e) determining a first decision (D 0 ) including a drilling location from said derived one or more target percentiles and a utility function for said ensemble of reservoir model; f) updating said ensemble of reservoir model with possible outputs of at least one pre-determined information scenario to create at least one temporary ensemble of reservoir model (E n ), wherein the temporary ensemble of reservoir model has a smaller uncertainty band than Eo; g) deriving at least one system performance output variable from an ensemble prediction of each temporary ensemble of reservoir model; h) determining at least one second decision including a drilling location for each of said temporary ensemble of reservoir model; i) calculating a value of information (VOI) for each information scenario wherein the VOI is the difference of said utility function between said second decision including a drilling location of that information scenario and said first decision including a drilling location; j) comparing said VOI for each information scenario; and, k) selecting an information scenario that matches the one or more target percentiles of said ensemble of reservoir model; and l) drilling the well at the location in the selected information scenario. a) framing a decision problem comprising a drilling location for an exploration, appraisal, development, or pilot well in a subsurface reservoir; b) uploading existing frame data, including permeability and porosity data, relating to the subsurface reservoir into a reservoir modeling program; c) generating and combining at least 2 realizations of said existing frame data to create an ensemble of reservoir model (E 0 ), wherein said ensemble of reservoir model defines an input uncertainty band; d) deriving at least one system performance output variable and one or more target percentiles of said system performance output variable from an ensemble prediction of the ensemble of reservoir model model; e) determining a first decision (D 0 ) including a drilling location from said derived one or more target percentiles and a utility function for said ensemble of reservoir model; f) updating said ensemble of reservoir model with possible outputs of at least one pre-determined information scenario to create at least one temporary ensemble of reservoir model (E n ), wherein the temporary ensemble of reservoir model has a smaller uncertainty band than Eo; g) deriving at least one system performance output variable from an ensemble prediction of each temporary ensemble of reservoir model; h) determining at least one second decision including a drilling location for each of said temporary ensemble of reservoir model; i) calculating a value of information (VOI) for each information scenario wherein the VOI is the difference of said utility function between said second decision including a drilling location of that information scenario and said first decision including a drilling location; j) comparing said VOI for each information scenario; and, k) selecting an information scenario that matches the one or more target percentiles of said ensemble of reservoir model; and l) drilling the well at the location in the selected information scenario. <EOS>