Published: June 2026 Technical Level: Advanced Category: Protection Systems
CYME (by Schneider Electric) and SKM PowerTools (by SKM Systems Analysis) address overlapping but distinct segments of the power system analysis software market. CYME is optimized for utility distribution system analysis (unbalanced three-phase feeders, overhead line modeling, distribution automation, and DER hosting capacity), while SKM PowerTools is optimized for industrial and commercial power system analysis (balanced three-phase systems, motor starting, arc flash per IEEE 1584-2018, and protection coordination for industrial switchgear). The two platforms overlap in the distribution-industrial interface: industrial facilities served from utility distribution systems, campus electrical infrastructure, and commercial building power systems have characteristics of both segments. This paper evaluates the technical capabilities of both platforms against the requirements of this interface segment, identifies the use cases where each platform provides a clear advantage, and addresses the arc flash analysis capability, where SKM PowerTools has the most complete IEEE 1584-2018 implementation available, as a specific differentiator.
The choice between CYME and SKM PowerTools is rarely straightforward for organizations whose work spans the utility-industrial interface. A consulting firm that designs distribution system interconnections for industrial facilities needs CYME's distribution modeling capabilities for the feeder analysis and SKM's industrial modeling capabilities for the facility power system analysis, and the firm must decide whether to maintain two platforms or to accept the limitations of using one platform for both segments.
The correct decision depends on where the majority of the firm's work lies. A firm primarily engaged in utility distribution planning that occasionally designs industrial facility power systems will find CYME adequate for the industrial work if the industrial facilities are served at distribution voltage and have conventional motor and drive loads. A firm primarily engaged in industrial facility design that occasionally performs distribution feeder studies will find SKM adequate for the utility work if the feeder studies are limited to steady-state analysis and arc flash, without hosting capacity or DER modeling requirements. Only a firm with substantial workloads in both segments needs to maintain both platforms.
SKM PowerTools implements a balanced three-phase Newton-Raphson load flow that is optimized for industrial and commercial systems: high-impedance networks with a small number of radial feeders, large motor loads, and power electronic loads (drives, UPS). The solver is highly reliable for convergence in stiff networks where the ratio of source impedance to load impedance is large. SKM's load flow also implements motor modeling that captures the reactive power demand of induction motor loads at partial load, which is important for power factor correction studies and for verifying voltage at motor terminals during starting.
CYME's load flow is the full three-phase unbalanced solver described in the preceding paper on the CYME-ETAP comparison. For industrial systems served by a three-phase balanced utility source, the unbalanced capability is unnecessary and CYME and SKM produce equivalent load flow results. For systems with significant single-phase loading (multiple single-phase lateral circuits serving the facility's perimeter buildings, single-phase welders or furnaces on the 480 V bus), CYME's unbalanced solver is more accurate.
SKM PowerTools has the most comprehensive motor starting analysis capability of any commercially available power system analysis software. The motor starting module models transient voltage during across-the-line and reduced-voltage starting (autotransformer, reactor, part-winding, wye-delta, solid-state), calculates the voltage dip at each bus in the system during the starting event, and evaluates whether the resulting voltage is within the manufacturer's recommended starting voltage range for motors elsewhere in the system. The motor starting study is a required deliverable for industrial power system designs per IEEE Standard 141 (Red Book), and SKM's implementation of this study is the industry reference.
CYME does not include a motor starting analysis module. For distribution feeder studies where motor starting is relevant (large HVAC motors starting on a residential or commercial feeder), CYME models the starting event as a voltage step change at the motor bus rather than as a transient dynamic event. This simplification is adequate for feeder voltage impact screening but not for the detailed motor starting analysis required for industrial facility design.
SKM PowerTools' arc flash module is the most complete implementation of IEEE 1584-2018 available in a commercial product, supporting all six electrode configuration classes (VCB, VCBB, HCB, VOA, HOA, and the spherical reference configuration), continuous-variable enclosure dimensions, automatic voltage interpolation for systems between 600 V and 15 kV, the 85 percent arcing current low-current instability check, and direct integration between the short-circuit study fault currents and the arc flash calculation without intermediate data transfer. For industrial facilities where arc flash analysis is a core deliverable, SKM's implementation is the industry standard.
CYME's arc flash module was introduced to serve distribution utility customers performing arc flash studies on their distribution switchgear and pad-mount transformer installations. The implementation covers the VCB and HCB configurations most commonly encountered in these applications but does not support the full set of IEEE 1584-2018 configuration classes required for comprehensive industrial arc flash analysis. Organizations performing arc flash studies on both utility distribution equipment and industrial facility equipment will find SKM more capable for the industrial portion of the work.
Both platforms provide comprehensive time-current coordination environments. SKM's coordination module has the larger industrial device library (circuit breakers, relays, and fuses from ABB, Eaton, GE, Schneider Electric, and Siemens with 50,000+ device entries) and is the preferred platform for industrial coordination studies where the primary devices are molded-case and insulated-case circuit breakers. CYME's coordination module has greater depth for distribution-class devices: reclosers, sectionalizers, and fuses used in utility distribution systems.
For organizations performing coordination studies that span from the utility substation relays through the distribution feeder to the industrial facility switchgear, neither platform provides complete native coverage of the full device range. The practical approach for most firms is to use CYME for the utility-side coordination study (substation through distribution feeder) and SKM for the industrial-side study (service entrance through branch circuit), with the interface between the two studies defined at the point of common coupling between the utility and the facility.
The analysis in this paper connects to several companion studies in this library. Readers concerned with the upstream and downstream engineering will find CYME and ETAP develops a closely related aspect of the same problem, while ETAP and SKM PowerTools extends the treatment into an adjacent domain. For the broader methodological context, SKM PowerTools versus EasyPower provides complementary depth.
CYME and SKM PowerTools are optimized for adjacent but distinct segments (CYME for utility distribution analysis of unbalanced overhead feeders and DER hosting capacity, SKM PowerTools for industrial and commercial balanced-system analysis, motor starting, and arc flash per IEEE 1584-2018), and the evaluation developed in this paper shows that the right choice follows directly from where a firm's work concentrates along the distribution-to-industrial spectrum. The central engineering conclusion is that the platforms overlap precisely at the distribution-industrial interface, where industrial facilities are served from utility distribution systems, and that firms operating heavily in that interface must weigh which platform's core strengths matter more for their deliverables. For the practicing engineer, the operative takeaway is that SKM PowerTools is the stronger tool when arc flash, motor starting, and industrial protection coordination dominate the workload, while CYME is the stronger tool when unbalanced distribution modeling and hosting capacity dominate, and that attempting to force either platform into the other's domain produces workflow friction that erodes the productivity the tool is meant to provide.
[1] IEEE Standard 141-1993, Recommended Practice for Electric Power Distribution for Industrial Plants (Red Book), IEEE, 1993.
[2] IEEE Standard 1584-2018, Guide for Performing Arc-Flash Hazard Calculations, IEEE, 2018.
[3] NFPA 70E, Standard for Electrical Safety in the Workplace, 2021 edition, NFPA, 2021.
[4] SKM Systems Analysis, PowerTools for Windows Technical Reference Manual, SKM, 2025.
[5] Schneider Electric, CYME Distribution Analysis Software: Technical Reference Manual, Schneider Electric, 2025.
[6] IEEE Standard 242-2001, Recommended Practice for Protection and Coordination of Industrial and Commercial Power Systems, IEEE, 2001.
[7] J. C. Das, Arc Flash Hazard Analysis and Mitigation, IEEE Press/Wiley, 2012.
[8] IEEE Standard 1547-2018, Standard for Interconnection and Interoperability of Distributed Energy Resources, IEEE, 2018.