Random number and assignment generation is pretty readily available and is also in most statistical packages, such as STATA. Powering clinical trials can be done with utilities built into statistical packages also; however, they do not address clustered and blocked designs. If that's a concern, you might be interested in Optimal Design software, which is distributed free of charge. See: http://sitemaker.umich.edu/group-based/optimal_design_software. For simpler problems, in addition to utilities in software packages, there is other free software on the internet for calculating statistical power. Bob

Thanks a lot Bob!

Any one aware if R has a package do randomization?

Dear Abdulla,

Randomization as a design doesnt need a software, If you mean free software for data anlysis of randomized trial, I suggest R package.

There is Winpepi. It can afford all types of randomization design. It is a free software. You can download it at this link :http://www.brixtonhealth.com/pepi4windows.html

Thanks Rabie

The problem with Bob and Rabie softwares that both cannot be installed and operated on Mac! Anything that work with Mac?

External, independent of any statistical package Random Allocation Software. http://random-allocation-software.software.informer.com/2.0/

Http://www.imim.cat/ofertadeserveis/software-public/granmo/

Almost all free statistical packages are developped for windows. You can try to run the softwares on mac by using some apps like PlayOnMac (http://www.playonmac.com/fr). I found this app on the net, I never tried it before.

There is also a free web application for basic statistical computing and Power estimation : http://www.openepi.com/oe2.3/menu/openepimenu.htm

Study Randomizer (https://studyrandomizer.com) provides this service, including permuted block randomization. It's an online service (IWRS), so you can use it for concealed allocation.

A bit late, but...

WINPEPI works perfectly on Mac/Linux (also Android) using the free program WINE (https://www.winehq.org/)