XML Design Consideration – What Should be used XML Elements or Attributes - BizTalk Schema Design Consideration

The choice of Element or Attribute for a data depends on different factors like -

1) Attributes take up only about half the space that elements take up.

This is because an attribute called OrderNumber will have the word OrderNumber only once, whereas

Element will have both a start tag and an end tag, meaning that the word OrderNumber will appear twice, in the opening and closing brackets for the tags. 

Hence the file size is comparable more if elements are used.

2) Elements can occur multiple times, attributes cannot, that is an element cannot contain multiple attributes with same name.

3) Property promotion in BizTalk works only for elements and not for attributes.

4) The structure of the external system to be integrated.

Links -

XML Elements, Attributes, and Types (XML Designer)

https://msdn.microsoft.com/en-IN/library/7f0tkwcx(v=vs.80).aspx