testing the stored procedure in sql server

I wrote one stored procedure for testing an another stored procedure by passing different parameters and storing the count and time taken for executing the procedure in temp table.Procedure is better than function?

CREATE PROCEDURE [dbo].[SPTEST_NEW] AS 
BEGIN
DECLARE @COUNT int;
DECLARE @STARTDATETIME DATETIME;
DECLARE @ENDDATETIME DATETIME;
DECLARE @TimeDiff NVARCHAR(50);
DECLARE @SPNAME VARCHAR(50);

DECLARE @Result TABLE
 (
  Cases NVARCHAR(100),
  RecordCount INT,
  ExecutionTime NVARCHAR(50)
 )
 DECLARE @Search TABLE
    (
            ID      NVARCHAR(50),
            NAME    NVARCHAR(200),
            FMT     NVARCHAR(100)
    )

 SET @SPNAME ='dbo.[SEARCH_VALUE]'; 
 SET @STARTDATETIME=GETDATE();

  --Case#1: Search by All

  INSERT INTO @Search
    EXEC @SPNAME
    @PRODUCTID =NULL,
    @PRODUCTNAME =NULL,
    @FORMAT =NULL

 SET @ENDDATETIME=GETDATE();  
 SELECT  @COUNT= @@ROWCOUNT
 SET @TimeDiff = CONVERT(TIME,@ENDDATETIME-@STARTDATETIME);
 INSERT INTO @Result values ('ALL', @COUNT,@TimeDiff)

 -- Case#2 : Search by Product-ID

 INSERT INTO @Search
   EXEC @SPNAME
    @PRODUCTID ='ABPROD-BLACK',
    @PRODUCTNAME =NULL,
    @FORMAT =NULL,

  SET @ENDDATETIME=GETDATE();
  SELECT  @COUNT= @@ROWCOUNT
  SET @TimeDiff = CONVERT(TIME,@ENDDATETIME-@STARTDATETIME);
  INSERT INTO @Result values ('PROD-ID:ABPROD-BLACK', @COUNT,@TimeDiff)

   --Case#3 : Search by FORMAT

   INSERT INTO @Search
   EXEC @SPNAME
    @PRODUCTID =NULL,
    @PRODUCTNAME =NULL,
    @FORMAT ='SCHT',

  SET @ENDDATETIME=GETDATE();
  SELECT  @COUNT= @@ROWCOUNT
  SET @TimeDiff = CONVERT(TIME,@ENDDATETIME-@STARTDATETIME);
  INSERT INTO @Result values ('Format:SCHT', @COUNT,@TimeDiff)
  SELECT * FROM  @Result
END

is above method is correct? or any other method.please suggest the method.