For a customer who has ordered a custom automated assembly line or a complex machine tool from an Indian OEM, the wait after the machine leaves the factory is a direct cost. A machine that sits on the customer’s shop floor in commissioning mode for eight weeks instead of four is six weeks of lost production capacity. For the OEM, extended commissioning means engineers on-site for longer than planned, accommodation and travel costs, and delayed payment milestones that are tied to acceptance.
The root cause of long commissioning cycles for automated machinery is almost always the same. PLC programs written for the nominal machine specification need to be debugged against the actual physical machine, which behaves slightly differently from the model. Sensor positions are adjusted. Travel limits need tuning. Interlocks that looked correct in the program logic create deadlocks in the actual sequence. Each of these issues has to be found and fixed during commissioning, one by one, with the machine physically present.
Virtual commissioning addresses this by moving the PLC debugging process to before the machine is installed.
A virtual commissioning setup consists of two components running in real time together. The actual PLC hardware or a software simulation of the PLC runs the actual machine program, the same code that will run on the final machine. Connected to this is a physics-based simulation model of the machine, typically built in a tool like Siemens Process Simulate or NX Mechatronics Concept Designer, that responds to the PLC outputs as the real machine would and sends sensor signals back to the PLC as if they were coming from physical sensors.
The programmer can run the machine program against the virtual model, watch the simulated machine execute the sequence, find the deadlocks and logic errors, and fix them before the physical machine exists. By the time the machine is actually built and installed at the customer site, the PLC program has already been debugged through hundreds of simulated cycles. Physical commissioning then becomes primarily a calibration exercise rather than a debugging exercise.
Indian manufacturers of automated assembly equipment, special purpose machines, and production lines who have adopted virtual commissioning report commissioning time reductions of 30 to 50% compared to their previous approach. The savings come from multiple sources.
PLC program quality at installation is higher because the obvious errors have already been found and fixed. The machine-specific tuning work that still needs to happen on-site goes faster because the program logic is already known to be correct and the physical work is focused on calibration. Customer handover happens faster, which improves the OEM’s relationship with the customer and triggers earlier payment against the commissioning milestone.
There is also a sales benefit that is less often discussed. An OEM that can demonstrate a virtual commissioning of a proposed machine during the sales process, showing the customer a simulation of exactly how the machine will work before it is built, has a compelling differentiator over competitors who can only show drawings and specifications.
Virtual commissioning requires investment in the simulation software and in the engineering time to build and maintain machine models. For machinery OEMs with a product portfolio, the model-building investment is amortized across multiple machines of the same type. For fully custom one-off machines, the investment needs to be weighed against the commissioning savings on that specific project.
The economic threshold where virtual commissioning clearly pays is for machines with complex sequential automation, more than 50 to 100 I/O points, and commissioning schedules that currently run longer than four weeks. Below this threshold, the model-building investment may not be recovered on a single project, though the learning investment still builds toward future projects.
For Indian machinery OEMs that are growing their export business and facing international customers with stricter commissioning time expectations, virtual commissioning is also a delivery quality commitment that differentiates them in competitive bid situations.
