Abstract:
The number of scientific publications related to alternative systems to the mass production in the last 20 years is abundant. Between the alternative systems proposed one which more academic popularity has enjoyed has been the lean manufacturing, although we do not have to forget other forms to call to productive systems that share many characteristics with the lean manufacturing (flexible manufacturing, agile manufacturing, mass customization, etc. Nevertheless the researches on each system seem to demonstrate that the practices to be used in each production system are similar or the same. 
The questionnaires found in literature to diagnose the degree of use of the practices of alternative systems to the mass production have concentrated in the lean manufacturing. Nevertheless the set of items used has varied remarkably from research to another one. A movement is still not appraised that converges towards the use, on the part of the researchers, of a few instruments whose validity and reliability have been resisted in different surroundings. In fact, the majority of the researches are based on ad-hoc questionnaires and few of them present a complete questionnaire validation, most of them present just the unidimensionality and the ?-Cronbach. Nevertheless, it seems to have consensus in identifying 5 great constructs that compose the lean manufacturing (TQM, internal production flow, maintenance, supply chain management and the implication of the workers). 
The objective of the companies when implanting the practices of the lean manufacturing is to improve its performance and to obtain a competitive advantage. The investigations on the effect of the practices of the lean manufacturing with the results have basically concentrated in the sectors of the automobile, electronic and machinery. Nevertheless to identify the practices that are related to results of the companies needs to be extended and to be verified in other sectors. 
Indeed, as the amount of publications about the alternative production systems to the mass production, we considered necessary this research that tries to realise several objectives. On the one hand to identify if the different names gave to the alternative systems to the mass production correspond to really different systems or if on the contrary the similarities are majors that the differences. 
On the other hand it has been identified and summarized the models of lean manufacturing identifying the way in which they defined the items in constructs or sub-scales of constructs. 
Later we have developed a questionnaire based in the items that appeared in the published models. Finally, we have realised the validation of sub-scales and models through a confirmatory factorial analysis, using data of a sample of Spanish Sheltered Work Centre’s (N=128). Of all the raised models, the best adjustment takes place with the first order model of 20 sub-scales. Finally it has been investigated, after the performance scale validation, the effect of the application of the lean manufacturing practices on the performance indicators of the companies defined in the sample. 
This work contributes an integrating vision comparing the alternative production systems to the mass production identifying the common practices of the systems found in the literature. Also we reviewed the models of the lean manufacturing previously published and the results of validity and reliability of the sub-scales found by other investigators, as well as the performance indicators used. Due to its confirming approach, this work can serve as generalization of studies that had been realised in contexts with different samples to which we have used for the replication.