L'intento del presente studio è stato quello di individuare il soggetto (o i soggetti) cui imputare i rapporti di lavoro nell'ambito delle imprese c.d. complesse. A tal uopo, in primo luogo, si è tentato di capire il significato di “impresa complessa”; in secondo luogo, si è indagato in ordine alla nozione di “datore di lavoro” accolta nel nostro ordinamento. Affrontate le questioni preliminari, l'analisi si è concentrata sulla risoluzione del quesito posto alla base della ricerca: chi è il datore di lavoro nell'impresa complessa? Una particolare considerazione è stata dedicata alle posizioni della dottrina e della giurisprudenza sulla teoria della codatorialità, la quale è stata esaminata anche in chiave comparata, al fine di trarre possibili spunti per un'eventuale trasposizione, nel sistema giuridico italiano, di soluzioni adottate da parte di altri ordinamenti. Una lettura in chiave evolutiva della subordinazione e, conseguentemente, della figura datoriale ha consentito di sposare la teoria della codatorialità, anche in ragione della sua adattabilità agli avveniristici modelli imprenditoriali dell'epoca delle piattaforme digitali che stiamo attraversando. / Main purpose of the research is to identify the subject (or the subjects) to which working relationships in complex companies must be allocated. In order to do so, firstly, meaning of "complex companies" has been analyzed. Then, notion of "employer"- as accepted in our legal system - has been explored. Once preliminary issues have been covered, the analysis focused on the main issue underlying the research/project: who is the employer in complex companies? Both doctrine and case law have been taken into consideration in analysing the “co-employer” theory. Said theory has also been studied under a comparative perspective in order to identify potential solutions for the transposition into the Italian legal system of ideas already adopted in other countries. At the end of the project/research, theory of "co-employer" has been accepted through an evolutionary analysis of the "subordination" concept as well as of the employer's role. Such a conclusion has been identified also in the light of its full adaptability to the new digital platforms' business models.

A l’heure de la globalisation des relations économiques, il est nécessaire que les décisions stratégiques soient prises au plus haut niveau, celui, dans un groupe, de la direction centrale. Or, construit autour du paradigme de la subordination juridique du salarié à l’égard de son employeur, le droit du travail néglige la dépendance économique, voire juridique, de ce dernier à l’égard d’entités juridiquement distinctes. L’employeur placé dans une telle situation peut voire ses choix stratégiques influencés ou commandés. S’esquisse alors l’image d’un « décisionnaire » étranger à la relation contractuelle nouée qui, néanmoins, influence l’exécution des relations de travail dans le groupe. Cette dichotomie dans l’adoption des décisions ne doit pas avoir pour corollaire l’oubli des responsabilités légitimes. Sans aller jusqu’à faire plier l’autonomie juridique des entités constituant le groupe, il convient d’en amender les effets pour que chacun assume les conséquences de ses décisions. Le droit ne peut rester indifférent au réel. / At a time of globalization of economic relations, strategic decisions have to be made on the highest level, that is, on the group's level. However, french employment law, which was built up around the paradigm of the employee's legal subordination to the employer, disregards the latter's economic or even legal dependence on other legal entities. Yet in such a situation, an employer's strategic choices may well be influenced or even dictated. Thus showing through are the outlines of an external decision-maker, third-party to the contractual relationship, who nonetheless influences the performance of the employment relationships within the group. This dichotomy in the decision-making process should not correlatively incur total oblivion as to the rightful responsibilities. Accordingly, without overriding the legal autonomy of corporate bodies, the legal consequences should be adapted so that everyone takes responsibility for their decisions.

L’entreprise naît en Droit d'un alliage complexe de notions juridiques (le contrat de travail, la personnalité morale, la représentation collective des travailleurs, etc...). L'ordonnancement systématique de celles-ci s'impose pour percevoir la cohérence de l'organisation juridique de celle-là. Des lignes de force se dégagent. Le contrat de travail oppose deux parties aux intérêts antagonistes. Mais la libération de la force de travail du salarié, partie de sa personne, et la pérennisation du lien contractuel les obligent à coopérer. Ce mouvement est renforcé par certains mécanismes étrangers à la nature du contrat de travail. Sont organisés le partage du contrôle de l’entreprise (lequel suppose d’assurer la représentation collective des travailleurs) et celui de ses utilités. Les salariés deviennent alors des quasi-associés. L'organisation juridique de l'entreprise n'est toutefois pas figée par le dogme. Des idéologies concurrentes en façonnent les contours. Certaines s'attachent aux fins. L'entreprise est alternativement mise au service de l'emploi et de l'activité d'entreprendre. D'autres s'intéressent aux moyens. Juristes et économistes prétendent à l'organisation scientifique de l'entreprise. / In Law, the firm is the result of a complex amalgam of legal concepts (employment contract, legal personality, collective representation of workers, etc.). The systematic ordering of these ones is needed to perceive the coherence of the legal organization of that one. Guidelines emerge. Employment contract is the meeting of two parties whose interests are antagonists. But the release of the labor force of the employee, part of his person , and the sustainability of the contract require them to cooperate. This trend is reinforced by some mechanisms non implied by the nature of the employment contract. Are shared the control of the company (which involves the collective representation of workers) and of its benefits. Employees then become nearly considered as the stockholders are. The legal structure of the firm , however, is not fixed by dogma. Competing ideologies are shaping it. Some focus on purposes. The company is alternately used as a means for employment and for the will of the enterpreneur. Others focus on methods. Lawyers and economists try to organize the firm scientifically.