Simulation-based Fault Injection in VHDL descriptions is increasingly common due to the popularity of top-down design flows exploiting this language. However, the large CPU time required to perform VHDL simulations often represents a major drawback stemming from the adoption of this method. This paper presents some techniques for reducing the time to perform the Fault Injection experiments. Static and dynamic methods are proposed to analyze the list of faults to be injected, and for removing faults as soon as their behavior is known. Common features available in most VHDL simulation environments are also exploited. Experimental results show that the proposed techniques are able to reduce the time required by a typical Fault Injection campaign by a factor ranging from 51% to 96%.