see - sc.judiciary.gov.ph/jurisprudence/2013/july2013/192394.pdf
"Under Article 280 of the Labor Code, as amended, a project employee is one whose “employment has been fixed for a specific project or undertaking the completion or termination of which has been determined at the time of the engagement of the employee or where the work or services to be performed is seasonal in nature and the employment is for the duration of the season.” Thus, the principal test used to determine whether employees are project employees is whether or not the employees were assigned to carry out a specific project or undertaking, the duration or scope of which was specified at the time the employees were engaged for that project.33
In the case at bar, petitioner worked continuously for more than two
years after the supposed three-month duration of his project employment for the NAIA II Project. While his appointment for said project allowed such extension since it specifically provided that in case his “services are still needed beyond the validity of [the] contract, the Company shall extend [his] services,” there was no subsequent contract or appointment that specified a particular duration for the extension. His services were just extended indefinitely until “Personnel Action Form – Project Employment” dated July 7, 1998 was issued to him which provided that his employment will end a few weeks later or on August 4, 1998. While for first three months, petitioner can be considered a project employee of PNCC, his employment thereafter, when his services were extended without any specification of as to the duration, made him a regular employee of PNCC. And his status as a regular employee was not affected by the fact that he was assigned to several other projects and there were intervals in between said projects since he enjoys security of tenure."