Information systems are partially defined by conceptual models. Conceptual models declare structures of concepts which need to be augmented with semantic logic in some form in order to get towards fully functional information systems. CoreWEB is an environment with a one button transformation of conceptual models with expressions declaring semantics, into executing information system. In CoreWEB, semantic logic is added to declared concepts by defining expressions (parameterless functions without side efects). In the executing information system, consistency of data as stated by expressions is maintained by an event driven data-flow mechanism.
Our research and development focus is on seamless life cycle management of Information Systems (is) which are semantically consistent with their users. As part of this efort, CoreWEB was developed as a tool for education, research and prototyping. Model driven development and execution of is has a long history [JE15; Pa04; PG92; Re77]. Automated transformation of is systems, from requirements and conceptual models, is available from some independent suppliers and has proven to work for full scale enterprise information systems. Documented benefits of automatic transformation of domain models, a category which includes conceptual information systems models, into software systems include lead time, cost and quality in an order of magnitude [MD08].
We consider pure conceptual models as declarations of structures of concepts, whereas semantic models also need definitions of the meaning of each concept. For information systems construction, we consider conceptual models describing structures of data to be suitable. For the purpose of automatic transformation of these models into information systems, formal machine readable definitions of concepts are required. I.e. rules regarding the concept and if the concept is a property, what is the rule for the value of this property. In many approaches, these kinds of rules are embedded in processing concepts separate from the data concept they afect, such as in object methods, object constraints, processes 2
To exemplify concept definition using expressions, a model of an order is used and the expression of calculating the price of the order as the sum of the price of the order items. In Fig. 1 the object types of the order is shown and their relations. The notation was developed for information modelling and is briefly explained in [JE19] page 10)
In this example, we define a tree graph of nodes and relations, with an expression calculating the sum of node values and the consecutive sum of all tree branches. Instead of the recursive tree traversal approach of imperative or functional languages, in the expressional data-flow approach nodes sum is just declared as the sum of its children plus it own value. Node object type and relations is shown in Fig. 3 Javascript pattern is in this case partly generated by selecting the relation (subnodes) and the property to summarise (tree value) and then adding the node value itself. Expression in javascript is shown in Fig. 4 and runtime system in Fig. 5
CoreWEB is an experimental environment which lacks several features that would be required for commercial use, however it demonstrates the concept of Models as Software. CoreWEB is currently used for teaching, semantic modelling and application prototyping in research, as well as for a tailor made and deployed system for a role play organisation with 600 members. A commercial environment based on similar principles, used to implement an ERP system is described in [JE15].
CoreWEB environment registration and some demonstration videos is available at https://www.ameis.se/cml. Educators and researchers are encouraged to use the free environment CoreWEB to model, execute and experiment with models. We urge researchers and practitioners with interest in model driven is to join in a triple helix efort https://www.ameis.se to develop and disseminate knowledge and practice. [JE15] [JE17]
Jonsson, T.; Enquist, H.: CoreEAF -A Model Driven Approach to Information Systems. In: CEUR Workshop Proceedings. CAISE2015. Vol. 1367, Stockholm, pp. 137–144, June 2015.
Jonsson, T.; Enquist, H.: Semantic Consistency in Enterprise Models-Through Seamless Modelling and Execution Support. In: CEUR Workshop Proceedings.
ER2017. Vol. Vol-1979, Valencia, p356–359, Nov. 2017. [JE19] [MD08] [Pa04] [PG92] [Re77] Mohagheghi, P.; Dehlen, V.: Where Is the Proof? - A Review of Experiences from Applying MDE in Industry. In (Schieferdecker, I.; Hartman, A., eds.): Model Driven Architecture – Foundations and Applications. Vol. 5095, Springer Berlin Heidelberg, Berlin, Heidelberg, pp. 432–443, 2008.