Lessons from DEPLOYment
  This paper reviews the major lessons learnt during two significant pilot projects by Bosch Research during the DEPLOY project. Principally, the use of a single formalism, even when it comes together with a rigorous refinement methodology like Event-B, cannot offer a complete solution. Unfortunately (but not unexpectedly), we cannot offer a panacea to cover every phase from requirements to code; in fact any specific formalism or language (or tool) should be used only where and when it is really suitable and not necessarily (and somehow forcibly) over the entire lifecycle. 
Manuel Mazzara, Cliff Jones, Alexei Iliasov
cs.SE