Expand description
§Precedence Network Analysis for Rust
§Precedence Networks
A Precedence Network (or Precedence diagram method) is a method of constructing connected
activivies in a directed graph that specify dependencies. By specifyfing the minmimum, expected and maximum duration of each task the network can be analysed to
find activities that sit on the critical path and must be completed on time to avoid delaying the entire network.
§Usage
Given the following precedence network
┌──────────┐
┌────────────────►│Document:4├─────────────────┐
│ └──────────┘ │
│ ▼
┌────┴───┐ ┌─────────┐ ┌──────┐ ┌────────┐
│Design:5├──────►│Develop:6├────►│Test:4├─────►│Deploy:1│
└────────┘ └──────┬──┘ └──────┘ └────────┘
│ ▲
│ ┌───────┐ │
└────────►│Train:3├─────────┘
└───────┘ Using precedence-net we can model it with the following code
use precedence_net::{Network, Result};
fn main() -> Result<()> {
let mut network_builder = Network::builder();
network_builder.add_activity("Design", 5.0)?;
network_builder.add_activity("Develop", 6.0)?;
network_builder.add_activity("Document", 4.0)?;
network_builder.add_activity("Deploy", 1.0)?;
network_builder.add_activity("Train", 3.0)?;
network_builder.add_activity("Test", 4.0)?;
network_builder.connect("Design", "Develop")?;
network_builder.connect("Design", "Document")?;
network_builder.connect("Develop", "Test")?;
network_builder.connect("Develop", "Train")?;
network_builder.connect("Test", "Deploy")?;
network_builder.connect("Train", "Deploy")?;
network_builder.connect("Document", "Deploy")?;
let network = Network::try_from(network_builder)?;
println!("Activity | Earliest Start | Earliest Finish | Latest Start | Latest Finish | Total Float | Free Float | Critical Path");
println!("---------------------------------------------------------------------------------------------------------------------");
for activity in network.activities()? {
println!(
"{:^8} | {:>14} | {:>15} | {:>12} | {:>13} | {:>11} | {:>10} | {:^14}",
activity,
network.earliest_start(activity)?,
network.earliest_finish(activity)?,
network.latest_start(activity)?,
network.latest_finish(activity)?,
network.total_float(activity)?,
network.free_float(activity)?,
network.on_critical_path(activity)?,
);
}
Ok(())
} will produce the following output
Activity | Earliest Start | Earliest Finish | Latest Start | Latest Finish | Total Float | Free Float | Critical Path
---------------------------------------------------------------------------------------------------------------------
Design | 0 | 5 | 0 | 5 | 0 | 0 | true
Develop | 5 | 11 | 5 | 11 | 0 | 0 | true
Document | 5 | 9 | 11 | 15 | 6 | 6 | false
Test | 11 | 15 | 11 | 15 | 0 | 0 | true
Train | 11 | 14 | 12 | 15 | 1 | 1 | false
Deploy | 15 | 16 | 15 | 16 | 0 | 0 | true §Performance
Using Criterion.rs the following activities were benchmarked for a precedence network of 62 500 activities on an Intel Core i7 with 16GB RAM.
- Adding activities to the network: 78ms
- Creating Network from Network Builder: 239ms
- Creating NetworkBuilder from Network: 44ms
- Retrieving Critical Path: 1.1ms
§To Implement
- Cyclic route checking
- Serialize and deserialize
- Update activities