What is the best tool to create use-case diagram and entity-relationship model?

Unfortunately the answer to this one is "It depends".  All UML tools will allow you to create use case diagrams, however, there are dozens of UML tools ranging from $0 to >> $10,000 out there.  You can see a list of many of these tools here (http://en.wikipedia.org/wiki/List_of_Unified_Modeling_Language_tools). I have yet to find a free UML tool that works for me, then again, I require that a UML tool be able to produce not only a use case diagram but also class, interaction, activity, and deployment diagrams.  I suspect if you only need use case diagrams then virtually all of the tools will work (even the free ones).  Note, the different tools vary in their focus:   - some focus on the meta-data others on drawing   - some allow forward or round trip engineering, others don't   - some will export to XMI, a UML format that can be transported to other tools You can find reasonable UML tools at between $1,000 and $2,000 a developer seat.  I have used the following:   - Enterprise Architect (good, but project focused)   - MagicDraw UML (good)   - Rational Rose (now Rational Rhapsody) (full featured, expensive)   - Visual Paradigm (good)   - Eclipse UML 2 (very basic)   - Microsoft Visio (rudimentary) Entity-relationship diagrams (ERD) usually go hand in hand with older methodologies (i.e. Data Flow Diagram (DFD)) and don't tend to be available in UML tools.  Again, depending on your requirements, you can use a tool as basic as Microsoft Visio or an ERD tool that will be vendor provided (i.e. SQL Server Database Management Studio).  You can find a list of database modeling tools here (http://www.databaseanswers.org/modelling_tools.htm). Some UML tools have a facility for creating database diagrams (e.g. Visual Paradim Plus) and will allow you to export SQL statements that can be used to initialize a database structure.   If a single tool is used for both sets of diagrams then make sure it does both diagrams well. If you already have Microsoft Visio then you might see how far it will take you, it will allow you to create basic web page structure diagrams. All things considered, if you don't have any tools you can start with the community edition (free) of Visual Paradigm and then see if you need more functionality than it provides. :-)

Use https://www.lucidchart.com/. The UML and ERD diagram libraries are both included as part of the free version and they just added some really cool features to the ERD shape library. You can simply run a query on your database management system to automatically generate entity relationship tables, and the column borders are dragable; so, it’s easy to make your diagrams look exactly like you want. I work for Lucid Software (which makes Lucidchart), and I created a tutorial on how to create http://support.lucidchart.com/entries/21606135-Entity-relationship-diagrams in Lucidchart. I hope you like it!

I prefer to use Rational Software Developer that I strongly recommend, but there are many other optionsI've listed them in three category below : open-source / vendor specific/ on-line Top open-source UML tools http://www.bouml.fr/BOUML is a free UML 2 tool box allowing you to specify and generate code in C++, Java, Idl, Php and Python https://www.modelio.org/Modelio is an open source modeling environment. Modelio delivers a broad-focused range of standards-based functionalists for software developers, analysts, designers, business architects and system architects. (GPL) http://www.eclipse.org/papyrus/Papyrus is aiming at providing an integrated and user-consumable environment for editing any kind of EMF model and particularly supporting UML and related modeling languages such as SysML and MARTE. (EPL) http://uml.sf.net/Umbrello UML Modeller is a Unified Modelling Language diagram program for KDE. (GPL) http://www.umldesigner.org/UML Designer provides a set of common diagrams to work with UML 2.5 models. The intent is to provide an easy way to make the transition from UML to domain specific modeling. (EPL) http://cruise.site.uottawa.ca/umple/Umple is technology for Model-Oriented Programming. It adds abstractions such as UML associations, attributes, and state machines to object-oriented programming languages such as Java, PHP and Ruby. (MIT) Top Vendor specific UML tools Rational Software Architect Rational Software Modeller IBM Rapsody Enterprise Architect There are many options the top 7 online website for UML design http://creately.com/Online diagramming and collaboration. Several modeling languages supported http://www.diagram.ly/ Simpe and easy https://www.draw.io/ http://www.gliffy.com/ https://www.lucidchart.com/ http://yuml.me/ http://www.jgraph.com/mxgraph.html Best Regards

Overall,Sparxseems to have established a strong reputation as a highly effective tool. Its enterprise architect framework has been rated as a very good tool for the complete life cycle modeling and development. The whole package can cover the complete software development lifecycle. Looking for the latest licensed version might be a challenge for the team.   Magic Draw and Visual Paradigm also deliver the needed output, the designs are less favorable than the enterprise architect. Thus, after initial assessment and revisiting the selection criteria, the team still favored Sparx.   Based on online demos and free trials, these tools produce easily generated diagrams and manage the relation between various samples in an intuitive manner. All of these three are candidates for our use-case modeling.

Give Edraw Max a try. It offers exact symbols and templates for https://www.edrawsoft.com/create-use-case-diagram.php and entity-relationship diagrams. It’s rather cool to use, no learning curve, and no drawing skills required. I use in on my Windows system, but it could also run on Mac and Linux. See - https://www.edrawsoft.com/erdiagram/

I worked with Umbrello and jUCMNav plugin in eclipse (Both Open Source softwares). Worked good for me.. Again, depends on your requirements and the kind of support you require from the tool.

Visual paradigm (http://www.visual-paradigm.com)

I can speak to Data modeling. I've found Embarcadero ERStudio to be the best tool for professional data modelers. If all you want are pretty pictures, anything will suffice, but if you do modeling for a living at an enterprise scale, you need a real modeling tool.

I agree with Dalip- I've used Visual Paradigm for a while and it's fairly easy to use.