Causal Codes Technical
Refers to physical items such as equipment, physical installations, software, materials, labels and forms.

Latent Errors Errors that result from underlying system failures

TEX	External	Technical failures beyond the control and responsibility of the investigating organization.
TD	Design	Inadequate design by of equipment, software or materials. Can include the design of workspace, software packages, blood drive set-up, forms and label design.
TC	Construction	Correct designs that were not constructed properly. Examples include incorrect set-up of blood drives and installation of equipment in an inaccessible area.
TM	Materials	Material defects found. Examples could be the weld seams on blood bags, defects in label adhesive, or ink smears on pre-printed labels or forms.