General Requirements Current Solution Areas for Improvement
Ability to search a collection of documents efficiently Reverse Indexing Faster Reindexing
Ability to search text without exact string specification Use Thesaurus to create a mapping of related words                                                                     
Ability to handle multiple file types Use COM Interops to read Word and Excel. Also able to read .txt and non-OCR .pdf's. Allow reading of PowerPoints
Multiple users must have access Small executable that indexs folders of a shared drive on each user's machine. Using a shared index for reduced indexing by users.
Must run on Windows Use C# with .NET libraries N/A
Rule-based search function GUI has multiple options for searching, including simple or advanced search. Search results are a combination of all keywords. Also uses stemming, synonym, and acronym searchs. Produce better results
Ability to preview documents A portion of the document that contains the keywords will be shown, and all keywords in that portion are (optionally) highlighted.  Better highlighting
Access to source file Preview has a right click option to open the actual file
Correlation between documents Correlation based on date created                     Add additional measurements of correlation.
Ability to handle scanned PDFs None implemented. Look into PDF OCR solution or other formats like .tiff or .mdi