Here’s how to estimate PLC and SCADA programming and software development costs in the context of industrial automation projects:
1. Break Down the Work:
Similar to a bottom-up estimating approach, divide the PLC and SCADA programming workload into smaller, more manageable tasks. This can include:
- I/O point configuration and programming
- Function block development
- Communication protocol setup
- HMI (Human-Machine Interface) design and development
- SCADA Screens Development, Faceplates Development, Library Objects Management, etc.
- SCADA Event logging and historical trending
- System testing and documentation
2. Estimate Effort per Task:
- Assign estimated time to complete each task based on:
- Complexity of the function (complex algorithms vs. simple logic)
- Programmer’s experience level (senior vs. junior)
- Industry standard times (if available)
- Consider using historical data from similar projects or internal data on programmer productivity if available.
3. Apply Labor Rates:
- Multiply the estimated time per task by the hourly or daily rate of the programmers involved.
- This will provide a cost estimate for each development task.
4. Include Additional Costs:
- Factor in the cost of required software licenses (PLC development software, SCADA software).
- Allocate budget for testing and validation efforts.
- Include a contingency buffer (5-10%) to account for unforeseen complexities or scope changes.
5. Considerations Beyond I/O Points:
While the number of I/O points (inputs and outputs) connected to the PLC can be a starting point for discussion, it shouldn’t be the sole factor for cost estimation. Complex logic development, HMI customization, and data management functionalities can significantly impact development time and cost, even with a relatively low number of I/O points.
Additional Tips:
- Involve the programmers in the estimation process to leverage their expertise and understanding of the project scope.
- Clearly define the functionalities and deliverables expected from the PLC and SCADA system to ensure a realistic estimate.
- Obtain quotes from external development firms if you plan to outsource the programming work.
By following these steps and considering these factors, you can develop a more comprehensive and realistic estimate for the PLC and SCADA programming and software development costs within your industrial automation project.
