randomforge

randomforge — Innovating the Future of Randomization

randomforge is an open, extensible framework for clinical trial randomization methods in R.
It provides a transparent and auditable core for implementing and using randomization procedures, starting with a flexible implementation of permuted block randomization and designed to grow into a broader ecosystem of randomization methods.

This package is the core engine of the wider randomforge initiative: a community-driven effort to innovate the future of clinical trial randomization.

🌍 Vision

Randomization is a cornerstone of clinical research integrity.
Yet many tools currently in use are:

• proprietary and closed,
• difficult to extend or integrate,
• opaque in how assignments are generated,
• and not designed for collaborative innovation.

randomforge aims to change this by providing an open, shared infrastructure for randomization methods – where ideas can grow into trusted, well-documented and practically usable methods, developed together by the community.

🔧 Current Capabilities (0.1.x)

The current version of randomforge focuses on a robust core for permuted block randomization (PBR), built with extensibility in mind.

Already implemented:

• Permuted block randomization (PBR) via getRandomMethodPBR()
  • Support for fixed and random block sizes
  • Support for multi-arm designs
• Configurable randomization projects
  • getRandomProject() to define a trial project
  • getRandomConfiguration() to configure treatment arms, seeds and buffer sizes
• In-memory randomization database
  • getRandomDataBase() to manage projects, configurations, results and subjects
  • S3 method as.data.frame.RandomDataBase() to inspect randomized subjects
• Stratification support at configuration and subject level
  • Stratum identifiers are automatically constructed from named factor levels
• Random allocation value service / buffer
  • getRandomAllocationValueService() to manage the underlying random number stream
• Excel export utilities
  • writeExcelFile() to export randomization or subject lists into an Excel file
• Helper utilities
  • getTreatmentArmValueList() to construct arm-specific values, e.g. for allocation ratios or block compositions

The internal architecture uses reference classes to represent key entities like RandomProject, RandomConfiguration, RandomBlock, RandomSubject, and RandomSystemState. This makes it easier to extend the engine to additional randomization methods in the future (e.g., covariate-adaptive or response-adaptive procedures).

🚀 Planned Extensions

While the current release focuses on permuted block randomization, the randomforge initiative is designed to cover a much wider range of techniques over time, including (but not limited to):

• baseline-adaptive and covariate-adaptive methods (e.g. minimization),
• response-adaptive randomization,
• more advanced stratification & centre structures,
• enhanced auditing and reporting facilities,
• integration with Shiny UIs and web APIs,
• validation and documentation patterns suitable for regulated environments.

🧪 Example: Simple Block Randomization

The example below illustrates a minimal workflow using the currently implemented PBR engine.
It shows how to:

• create a project and configuration,
• choose a block randomization method,
• repeatedly request the next randomization result,
• inspect the resulting subject-level randomization in a data frame.

library(randomforge)

# Create an in-memory randomization database
randomDataBase <- getRandomDataBase()

# Define a project and configuration
randomProject <- getRandomProject("Example Trial")
randomDataBase$persist(randomProject)

# Create a randomization configuration
config <- getRandomConfiguration(
    randomProject        = randomProject,
    treatmentArmIds      = c("A", "B"),
    seed                 = createSeed(),
    ravBufferMinimumSize = 1000L,
    ravBufferMaximumSize = 10000L
)
config

randomDataBase$persist(config)

# Define variable block sizes
blockSizes <- getBlockSizes(config$treatmentArmIds, c(4, 6))

# Define a block randomization method
blockSizeRandomizer <- getRandomBlockSizeRandomizer(blockSizes)
blockSizeRandomizer

randomMethodPBR <- getRandomMethodPBR(
    blockSizes              = blockSizes,
    fixedBlockDesignEnabled = FALSE,
    blockSizeRandomizer     = blockSizeRandomizer
)

# Create a random allocation value service
ravService <- getRandomAllocationValueService()
ravService$createNewRandomAllocationValues(config)

# Visualize the distribution of the random allocation values
plot(ravService, usedValuesOnly = FALSE)

# Create a few randomization results
lapply(1:5, function(i) {
    getNextRandomResult(
        randomDataBase               = randomDataBase,
        randomProject                = randomProject,
        randomMethod                 = randomMethodPBR,
        randomAllocationValueService = ravService
    )
})

# Convert results to a data frame
as.data.frame(randomDataBase)

📦 Installation

At this stage, randomforge is not yet on CRAN. You can install the development version from GitHub:

# install.packages("remotes")
remotes::install_github("RCONIS/randomforge")