respectively (Refer to supporting information S5). We did this to simulate a situation where the staff started working with no problems but faced them increasingly over time. The value of efficiency of support system were simulated with 50% all the time, with this parameter we simulate a system with 50 percent deficiency. We present two situations based on the outcomes of simulating the model (figure 2). In the first situation labeled as ‘‘planned’’, we assume the lack of an error in the work done. The simulation results represent CRFs to be done and CRFs completed. In the second situation labeled as ‘‘Simulated with Rework’’ we attempted to simulate of what happened on observed environ- ment. This simulation was based on three emergent themes presented in this manuscript. In this second situation work could not be completed as planned. This was primarily a consequence of rework that was generated because of error fraction caused by emergent themes consequences (rework point on figure 2). Policy Model Results The policy model results were divided into three categories of policies with an aim to reduce the rework: (a) Standardized process procedure, (b) Integration of application systems, (c) Improvement of support systems (figure 3). In ‘‘standardized process procedure’’ policy, we suggest the clinical trial administrative staff of each site to periodically revise their standard procedures and perform training with the research team when working with CRFs to Workflow in Clinical Trial Sites and Data Quality decrease the creation of intermediate documents. For the policy ‘‘integration of application systems’’ the clinical trial administra- tive staff must work together with IT staff of a site and analyse all the data repositories created in duplicity (as observed during our ethnographic study) and create a solution where the clinical trial staff will insert information in only one application to avoid these duplicities. Finally, in the ‘‘improvement of support systems’’ policy, the clinical trial administrative staff and sponsors need to work more efficiently to obtain support information more fast and friendly when working with CRF. For each one of these policies the PI, CRC’s, nurses, pharmacists and receptionist involved in clinical trial procedures must be trained in new methods and procedures that can facilitate the use of information and resources more efficiently while reducing rework. As a result of policies applied (figure 4), we observe the latter leads to more CRF’s completed, resulting in less rework. Rework does not disappear altogether but reduces. In course of time, if policies are well implemented, rework should tend towards zero. Figure 5 gives us an idea of workflow behaviour in our simulation. The dotted line represents workflow planned, which should be complete a thousand of CRFs for ten months. The straight line represents the simulation performed with rework caused by three emerging themes identified. In this situation, the workflow has been increased in order to be able to complete a thousand CRFs which will need twelve months. The dotted line Figure 2. CRF’s to do and CRF’s completed in two situations: planned and simulated with rework. doi:10.1371/journal.pone.0039671.g002 PLoS ONE | www.plosone.org 6 June 2012 | Volume 7 | Issue 6 | e39671