The phrase "as a main factor" is correct and usable in written English.
It can be used when discussing the importance or significance of a particular element in a situation or analysis.
Example: "In the success of the project, communication was identified as a main factor contributing to the team's efficiency."
Alternatives: "as a key element" or "as a primary influence".
"From now on, all Olympics will dig deep in their pocket in budgeting for security as a main factor," the Greek defense minister, Spilios Spiliotopoulos, said last week.
Other veterans of those battles cite lobbying by the domestic automakers as a main factor in the failure of Mr. Markey's legislation.
When Bryant received the M.V.P. award, between Lakers victories in Games 1 and 2 of this best-of-seven series, he singled out the Gasol trade as a main factor behind his success and the swift ascension of the Lakers, who were seventh in the conference last season.
More broadly, criminologists have cited the bleak economic picture in much of upstate and western New York as a main factor in the region's crime troubles, which have affected Lockport, Niagara Falls and other parts of Niagara County, among other places.
Tumor size was not considered as a main factor in the Cameron's scoring system.
are introduced as a main factor affecting vertical coordination and supply-chain performance.
Wanting to connect with people is also a main factor as to why I write and publish things, forgot to mention that.
Except for atpcl in the long-term feeding treatment, the minimal explanatory model never retained time as a significant main factor or a significant interaction.
Effects on path length and spatial strategy use were assessed using repeated measurements anova with day as a second main factor.
Including ant species as an additional main factor allowed us to extend the analysis to a full three-way ANOVA for four ant species.
The limited availability of soil information has been recognized as a main limiting factor in digital soil mapping (DSM) studies.
