Developing  efficient  and  effective  decision  making support  includes  identifying  means  to  reduce  repeated  manual work  and  providing  possibilities  to  take  advantage  of  the  experience  gained  in  previous  decision  situations.  For  this  to  be possible,  there  is  a  need  to  explicitly  model  the  context  of  a decision  case,  for  example  to  determine  how  much  the  evidence from one decision case can be trusted in another, similar context. In earlier work, context has been recognized as important when transferring  and  understanding  outcomes  between  cases.  The contribution of this paper is threefold. First, we describe different ways   of   utilizing   context   in   an   envisioned   decision   support system.  Thereby,  we  distinguish  between  internal  and  external context  usage,  possibilities  of  context  representation,  and  context  inheritance.  Second,  we  present  a  systematically  developed context  model  comprised  of  five  types  of  context  information, namely organization, product, stakeholder, development method &  technology,  and  market  &  business.  Third,  we  exemplary illustrate the relation of the context information to architectural decision  making  using  existing  literature.