The NETFLOW procedure creates and initializes a SAS macro variable called _ORNETFL. After exiting the procedure, you can use
%put &_ORNETFL;
to view details about the optimization.
When the network simplex method is used, the value of _ORNETFL consists of the following parts:
ERROR_STATUS, indicating the existence or absence of any errors
OPT_STATUS, the stage of the optimization, or what solution has been found
Ideally, at the end of a PROC NETFLOW run in which the network simplex method is used, _ORNETFL has the following value:
ERROR_STATUS=OK OPT_STATUS=OPTIMAL OBJECTIVE=x SOLUTION=OPTIMAL
At the end of a PROC NETFLOW run in which the interior point algorithm is used, _ORNETFL should have the following value:
ERROR_STATUS=OK SOLUTION=OPTIMAL OBJECTIVE=x ITERATIONS=x ITERATING_TIME=x SOLUTION_TIME=x
Nontrailing blank characters that are unnecessary are removed.
If the preprocessor detects that a problem with a network component is infeasible, and you specify that the interior point algorithm should be used, _ORNETFL has the following value:
ERROR_STATUS=OK SOLUTION=INFEASIBLE ITERATIONS=0 ITERATING_TIME=0 SOLUTION_TIME=0
The same value is assigned to the _ORNETFL macro variable if the preprocessor detects that an LP problem is infeasible.
Table 6.6 lists alternate values for the _ORNETFL value parts.
Table 6.6: PROC NETFLOW _ORNETFL Macro Values
Keyword 
Value 
Meaning 

ERROR_STATUS 
OK 
No errors 
MEMORY 
Memory request failed 

IO 
Input/output error 

DATA 
Error in the data 

BUG 
Error with PROC NETFLOW 

SEMANTIC 
Semantic error 

SYNTAX 
Syntax error 

UNKNOWN 
Unknown error 

OPT_STATUS 
START 
No optimization has been done 
STAGE_1 
Performing stage 1 optimization 

UNCON_OPT 
Reached unconstrained optimum, 

STAGE_2 
Performing stage 2 optimization 

OPTIMAL 
Reached the optimum 

OBJECTIVE 
objective 
Total cost or profit 
MINFLOW 
minflow 

MAXFLOW 
maxflow 
If MAXFLOW is specified 
SHORTEST_PATH 
shortpath 
If SHORTPATH is specified 
LONGEST_PATH 
longpath 

SOLUTION 
NONOPTIMAL 
More optimization is required 
STAGE_2_REQUIRED 
Reached unconstrained optimum, 

OPTIMAL 
Have determined the optimum 

INFEASIBLE 
Infeasible; no solution exists 

UNRESOLVED_OPTIMALITY_OR_FEASIBILITY 
The optimization process stops 

MAXITERB_OPTION_STOPPED_OPTIMIZATION 
The interior point algorithm stops after performing maximal 