| Non-competitive procurement procedures | Eßig and Glas (2015) |
| Increasing award volumes lead to disadvantageous admission requirements for larger business sizes; large contract volumes | Eßig and Glas (2015); Allen (2021); Schiele (2020); European Commission (2016) |
| Proposal phase involves high costs and is perceived as time-consuming; procurement process is costly, time-consuming, and outcome uncertain | European Commission (2021b); Loader (2013); Woldesenbet and Worthington (2019) |
| Conflicting priorities usually result in a focus on efficiency and return or cost (savings) | Harland et al. (2019) |
| Narrow definition of return and costs; slow payment; lack of feedback; price and contract size; meeting the requirements of large contracts | Loader (2013); Loader and Norton (2015); European Commission (2021b); Vluggen et al. (2019) |
| Poorly formulated selection criteria; lack of information on the proposed solution; absence of measurement mechanisms | European Commission (2021b); Manunza (2018) Aboelazm (2023) |
| Lack of understanding public procurement principles and knowledge of tendering strategies for success | Evans et al. (2022) |