1. A process analysis method for estimating the similarity between at least two clinical processes, comprising the steps of: forming a plurality of two-dimensional clinical process matrixes each of which maps rendered clinical service quantity data for one clinical process into cells coordinated by an axis marked by types of rendered clinical services and another axis marked by points in time t when the clinical services are rendered, respectively, and each of the cells containing a rendered clinical service quantity of a j type of rendered clinical services at an i time point is set to be as a matrix element M(i, j); calculating a similarity between at least two clinical processes each defined by a metric by selectively extracting between the respective matrix elements therein the and estimating the similarity between at least two of said clinical processes by using the calculated similarity between said clinical processes, wherein the similarity between said clinical processes is estimated, using a computing device having a processor, by the steps of: profiling said clinical processes into functions defined by said selectively extracted respective matrix elements; convoluting said functions with a broadening function on a time-dimension which corresponds to said points in time when the clinical services are rendered; calculating differences of the convoluted functions; calculating a root of square integral of the differences thereby estimating the similarity between said at least two of said clinical processes; extracting a similar clinical process group among said at least two clinical processes based on said estimated similarity between said at least two clinical processes thereby establishing a treatment plan or a clinical pathway which consists of clinical processes that are determined to provide optimal healthcare options and which is presented in a schedule summarizing clinical services conducted during said clinical processes.