The following general guidelines are recommended to increase the success rate of request processing.

XML for all requests should be validated against the provided XSD before submission to the web service layer.

Data validation should be done by the interface collecting any data from a consumer prior to that data being included in any XML and submitted to the web service layer. This data validation should use a combination of the data types defined in the XSD for the request that the data is being collected for, as well as common sense logic based on the business case for the collection of the data from the consumer (for example, order numbers for an order detail request should only contain numeric values).

XML submitted to the web service layer should always be valid XML and should follow the web industry standards for encoding any data submitted in the XML (see http://www.w3schools.com/xml/xml_encoding.asp). Any character values that are illegal in an XML document should be handled properly in the construction of the XML message prior to submitting the XML (see http://www.w3schools.com/xml/xml_cdata.asp).

XML requests should always submit any predefined literal (or code) values when required, as specified in the detailed documentation for each API.

Logging is highly valuable for visibility and troubleshooting issues and is strongly recommended. Log each of the full XML payload requests and responses produced as part of order submission process for each order.