In the 1970s, the PLC came up for the first time in the field of manufacturing by replacing hardwired control logics and became indispensable in todays industrial automation. Several definitions of programming languages for PLCs were developed, which later, due to lacking clarity, were combined and harmonised into the IEC 61131 standard. As a successor of the IEC 61131, the IEC 61499 was designed enabled the creation of moduleand component-based systems. In implementations of todays industrial automation systems both standards are used, which raises the question on the suitability of IEC 61131 and IEC 61499 for typical classes of applications. This work proposes a systematic comparison based on software metrics between IEC 61131 and IEC 61499 with the aim of discussing their suitability for typical applications in industrial automation. In order to ensure fair conditions, an IEC 61131 run-time environment is derived from FORTE. Additionally, a test PLC is set up, which is used to execute programs in both standards. Both implementations are then evaluated via McCabes Cyclomatic Complexity and the Halstead software measures, providing an objective comparison. The sequential task implemented in IEC 61499 has a 73% reduced program effort compared to its IEC 61131-3 FBD/ST analogon. Hence, the IEC 61499 standard is better suited for sequencer applications. However, for the continuous task the IEC 61131-3 is better suited for the implementation. This is because, even though the program difficulty is 27% higher than in the case of IEC 61499, the IEC 61131-3 FBD/ST implementation shows a program effort reduced by 37%.