Process Steps > Process and Step Validation

Process and Step Validation
Before a process can be executed successfully, each step of the process and the relationships between the steps must be set up correctly. Validation is the process where the Process Designer verifies that the steps and links have certain fundamental requirements. Validation can occur at two levels:
Process – Process Designer checks the entire process.
Step – Process Designer checks an individual step.
Validating a Process
Click Validate on the toolbar or select Validate Process from the Tools menu.
Process Designer checks these aspects of the process to see if certain basic essential elements are present and accurate.
 
Process Designer checks to be certain your process does not contain recursive logic that would result in an infinite loop. This causes the validation to fail.
Unconnected Steps – Steps that are not linked to anything. These unconnected steps causes a warning to be issued. It simply tells you, "Warning: Step 'X' is unconnected." It does not cause the validation to fail.
Unterminated Steps – Steps that are linked, but do not connect (through other links) to the Stop step. If you have unterminated steps, you may receive a message telling you which steps are unterminated, and the validation fails.
Process Designer checks to make sure the process contains a Start and a Stop step. If a Start or Stop step is missing, the process fails validation, and an error message is displayed.
Process Designer checks to make certain that all steps end at the Stop step. If not, the validation fails, and an error message is displayed.
Process Designer checks to make certain that all steps except the Start step have a preceding step. If the Start step is not connected to the other steps, or if it is not the first step, the validation fails and a message says, "The first step is not the Start step."
Process Designer checks to be certain that all Decision steps have at least one true branch and one false branch. If not, a message tells you which step is missing a branch, and the validation fails.
Process Designer validates each individual step according to that step's validation rules. If the step is not valid, the process validation fails, and a message tells you which step is invalid. If a step that is skipped is invalid, you receive a message telling you it is invalid, but the process validation does not fail.
If certain aspects are missing or incorrect, a warning message informs you of the problem. If other more important aspects are incorrect or missing, validation fails. A message displays, saying the process is invalid, and gives information explaining why it is invalid.
Validating a Step
Right-click the step icon and select Validate Step.
Note that if you instead select Tools > Validate Process, or click the Validate icon, then all process steps are validated along with other aspects of the process.
The following table gives step validation details for each type of process step.
 
Process Designer checks to make sure you have specified a transformation. If you did not specify a transformation, the validation fails and you receive a message: "Transformation Step Name does not have a transformation selected." Validation only checks that the transformation exists, not that the map is valid.
Process Designer checks the command line to make sure that there is one. If not, validation fails, and you receive a message telling you which step has a missing command line.
If there is a single line expression, the Process Designer checks to make sure it can evaluate to a number or a Boolean value. If there is no expression, or it does not have correct syntax for a true/false evaluation, then you receive a message to that effect and the validation fails.
If there is a multiple line expression, step validation is not available. If you choose Validate, it attempts to compile the expression. If it compiles, this message is displayed:
Process Designer checks to see that a session has been selected, and either a SQL statement or a path to a file has been entered. If not, a message informs you of the problem, and the validation fails.
If there is an expression or a file indicated, Process Designer checks to make sure the syntax is correct. If not, a message informs you, and the validation fails.
Process Designer checks to make sure there is an expression or a file entered, and also checks the syntax of the expression. If there is no expression or file indicated, or the expression syntax is incorrect, you receive a message to that effect and the validation fails.
Process Designer checks whether a DTS package is selected and that it can find it. If it cannot, you receive the message "Package not found."
If you try to validate a DTS step on a Unix system, you receive the message "DTS Steps not supported on this platform."
Process Designer checks whether a process name has been selected and calls for validation of that process. Warnings or messages associated with subprocess validation appear between the messages "Subprocess Name validating" and "Subprocess Name finished validating." See Also: “Validator Step”.