MODEL:
! Data Envelopment Analysis of Decision Maker Efficiency ;
! Keywords: DEA, Data Envelopment Analysis, Efficiency, 
           Pareto optimal, Benchmarking;
SETS:
  DMU: !The decisionmaking units;
    SLK,  ! Slack variable on SCORE(k) <= 1;
    SCORE; ! Each decision making unit has a
               score to be computed;
  FACTOR: TW;
! There is a set of factors, input & output;
  DXF( DMU, FACTOR):  F, ! F( I, J) = Jth factor of DMU I;
         W;  ! Weights used to compute DMU I's score;
ENDSETS

DATA:
  DMU = BL HW NT OP YK EL;  ! The schools;
! Inputs are spending/pupil, % not low income;
! Outputs are Writing score and Science score;
  NINPUTS = 2;  ! The first NINPUTS factors are inputs;
 FACTOR= COST RICH      WRIT  SCIN;
!      The inputs,    the outputs;
  F  =  89.39  64.3     25.2   223  ! BL;
        86.25  99       28.2   287  ! HW;
       108.13  99.6     29.4   317  ! NT;
       106.38  96       26.4   291  ! OP;
        62.40  96.2     27.2   295  ! YK;
        47.19  79.9     25.5   222; ! EL;
  WGTMIN = .0005; ! Min weight applied to every factor;
  BIGM = 999999;  ! Biggest a weight can be;
  EPSILON  = .000001; ! Zero tolerance;
ENDDATA
!----------------------------------------------------------;

 SUBMODEL DEA:
! The Model;
!  IU = DMU we are currently considering;
!  Try to make the score of DMU IU as high as possible;
  MAX = TSCORE;
    TSCORE = @SUM( FACTOR(J)|J #GT# NINPUTS:
                          F(INOW, J)* TW( J));

! Sum of inputs(denominator) = 1;
   [SUM21] @SUM( FACTOR( J)| J #LE# NINPUTS: F( INOW, J)* TW( J)) = 1;

! Using DMU IU's weights, no DMU can score better than 1
  Note, Numer/Denom <= 1 implies Numer <= Denom;
   @FOR( DMU( K):
      [LE1] @SUM( FACTOR( J)| J #GT# NINPUTS: F( K, J) * TW( J)) +
      SLK(K)= @SUM( FACTOR( J)| J #LE# NINPUTS: F( K, J) * TW( J))
   );

! The weights, TW( ),  must be greater than zero;
  @FOR( FACTOR( j): @BND( WGTMIN, TW(j), BIGM));
ENDSUBMODEL


CALC:
   @SET( 'TERSEO', 2);  !Minimal output;
   !Write out a solution report;
   @WRITE( @NEWLINE( 2),
      32*' ','Factor Weight:', @NEWLINE( 1),
      '     DMU    Score'
   );
   @FOR( FACTOR( I):  @WRITE( '       ',  FACTOR( I)));
   @WRITE('  Dominated by some combination of...');
   @WRITE( @NEWLINE( 1));

   ! Solve the DEA model for each DMU D;
   @FOR( DMU( D): 
      INOW = D;
      @SOLVE( DEA);  ! Solve the model above;
      @WRITE( '      ', DMU( D), '   ', @FORMAT( TSCORE, '6.3f'), '   '); 
      @FOR( FACTOR( I): 
         @WRITE( @FORMAT( TW(I), '8.4f'), '   ')
      );
      @IFC( TSCORE #LT# 1 - EPSILON: ! Does D get a score < 1? ;
        @FOR( DMU(k) | k #NE# D:     ! Yes, find those k that get a score of 1, ;
          @IFC( SLK(k) #LE# EPSILON: !   using D's weights. These k dominate D;
            @WRITE( ' ', DMU(k));
              );
             );
           );
      @WRITE( @NEWLINE( 1));
        );
ENDCALC

END