A shop floor controller class for computer-integrated manufacturing

High costs and long cycle times of software development are factors hindering the analysis and design of the complete cognitive aspects related to task performances. Reusable software has been proposed as a solution to the problem of high software development and maintenance costs. One of the paradigms for reusable software, object-oriented modelling, has emerged as an important method for specifying, creating and reusing software modules. Using Unified Modelling Language, this paper develops an object-oriented cognitive task analysis and design (OOCTAD) model based on human information-processing theory. First, human task performance-related cognitive aspects are classified into modules and logically linked together; secondly, cognitive aspects within these modules were further decomposed into packages and classes based on object-oriented technology. Finally, one case study was presented to compare and contrast different cognitive analysis models to illustrate the advantages of the OOCTAD model developed in the current research over the other five cognitive task analysis models. These reusable classes in the OOCATD model were shown to be reused to reduce software development costs and cycle times for cognitive task analysis and design. The current research should be of use to both developers and users of cognitively based tasks, systems and tools and researchers and practitioners in the broader discipline of cognitive tasks design and analysis.

In this paper, we identify a set of factors that may be used to forecast software productivity and software development time. Software productivity was measured in function points per person hours, and software development time was measured in number of elapsed days. Using field data on over 130 field software projects from various industries, we empirically test the impact of team size, integrated computer aided software engineering (ICASE) tools, software development type, software development platform, and programming language type on the software development productivity and development time. Our results indicate that team size, software development type, software development platform, and programming language type significantly impact software development productivity. However, only team size significantly impacts software development time. Our results indicate that effective management of software development teams, and using different management strategies for different software development type environments may improve software development productivity.

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The variety and complexity of processes required to be controlled in modern manufacturing places heavy demands on PLCs. To meet these demands PLC manufacturers are producing increasingly more powerful PLCs which require more complex programming languages. These complex programming languages result in longer specialised training and familiarisation times. To overcome these problems, the PLC programming language standard IEC 1131-3 was created. The standard details the workings of languages which provide PLC users with a set of programming languages based around familiar PLC concepts, but with language constructs similar to those of current generation PC programming languages. This paper describes the work done in a TCS partnership between Elite Control Systems Ltd. and Napier University to examine the viability of using structured methods for developing PLC software. Object oriented methods have established themselves as the future of software development for high level language users. We discuss how the object modelling technique of Rumbaugh et al. (1991) [one of the principal object oriented methods used in the UK] can be adapted for the creation of PLC software, and how the resulting practices differ from traditional PLC software development. We then describe the improvements in terms of software quality, development time, development costs, and maintainability that we have observed by adopting these techniques.

Ever-stricter environmental legislation over the past decade has led to the emergence of the end-of-life (EOL) industrial sector, e.g. remanufacturing of products, recycling of material and the recovery of energy. Due to uncertainties over returned product quantities, product quality and product diversity, production planning and control in EOL activities is quite different from those in the forward supply chain. In fact, those uncertainties can be diminished by enhancing the exploitation of the related information generated throughout the product lifecycle. Product lifecycle management provides an opportunity to access and share the distributed information generally available in the product lifecycle, while agent-based systems have been found to be effective tools in such large, uncertain environments. In this article, a product lifecycle information system that deploys agents is introduced into a typical EOL shop floor control system to provide lifecycle information for the returned product for decision-making. Supported by radio frequency identification technology, the product itself controls processes aggressively and autonomously in a system designed to minimise uncertainty. A case study of how the system supports shop floor planning and control in a plastics recycling plant is described at the end of the article.

The impact of software product lines to software development and maintenance costs has been well documented. Reduced time to market and number of people required to develop and support a company's software products constitute some of these savings. However, the actual savings model is more than just savings within the software development community. In fact, the savings realized directly by the software community may not be the biggest savings in the company. At Cummins Inc., we have realized impacts outside of embedded software development because of the use of software product lines. Service tool development costs for a product within the product line is 10% of those products outside the product line. Other impacts in areas like customer engineering, technician efficiency, calibration development, service engineering, management, and customer satisfaction are often harder to quantify, but these areas reap positive benefits from the product line architecture. This brings more of a business level to product line engineering.

Pattern-based framework for modularized software development and evolution robustness

As the existing control architectures for FMS have many problems with respect to flexibility, re-configuration and software development, which become worse as the system size increases, the international IMS research programme proposed a new manufacturing philosophy called the Holonic Manufacturing System (HMS). Under the notion of HMS, manufacturing systems are built from a modular mix of standardised, autonomous and co-operative agents called holons. Inspired by such emerging concept, we carried out this research with the aim of devising a holonic control framework, which is suitable for future FMS shop floor scheduling and control. This paper addresses the design of the proposed framework as well as the underlying holonic philosophy. In order to verify the applicability of the framework, an experimental simulation system has been developed on a real-time and distributed computer platform. The system consists of a set of holon prototypes capable of performing real-time scheduling for both manufacturing and transportation tasks, and a collection of interacting software modules that assist the simulation running on these prototypes. Experimental results acquired from the simulation have demonstrated that the framework is extensible and re-configurable. Implementation of the simulation system also provides direction and a workable foundation for further research and development on HMS.

Effort estimation is the process of predicting a software's likely cost and development time. Estimating software development effort is still a complex problem that receives a lot of research attention. The accuracy with which the effort necessary for software development is estimated, and it is a significant success element in software project management. The estimated effort should be roughly equal to the actual effort in a good software estimation model. Accurate estimation enables managers to allocate resources for the planning and coordination of all activities. In this paper the effort estimation for small size projects involving technical and analytical aspects of engineering intent. The estimation of time resources is done in three steps firstly Identification of seven novel traits of software (LOC, N&C, CGPA, R, CC, AC, FP). Secondly PCA was implemented to decide the significant parameters among the software features. Lastly linear regression and polynomial regression models were developed using the significant features predicted by the PCA. The result of evaluation of the two models are encouraging with the minimum RMSE of 32-204 minutes and maximum regression coefficients(r <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) of 0.95-0.98

COCOMO II is a method to get effort, time (schedule), and cost for software development. In this study, COCOMO II was used to obtain personnel direct costs of a software development project. Personnel direct costs were one of the three components that compose the owner estimate cost. The purpose of this study was to propose a conceptual model to determine the owner estimate cost that was formed from three components, namely: personnel direct cost, non-personnel direct costs, and taxes. In this study, it was explained the stages of using the model to determine the owner estimate cost for software development projects.

Cloud computing is less expensive than traditional on-premise computing for users, as it provides accessibility and reliability options for users and scalable sales for provider. But, like most things in life, the benefits come with risks. It's just a matter of knowing if the benefits outweigh the risks and vice versa. Unfortunately, the cloud computing does not escape to this universal rule. Then, it is important to consider the security of the cloud. As a solution to protect the cloud from security issues [1, 2, 3, 4], we think that IDSs integrated in the cloud remains among the best solution. We will also present an architecture based IDS that respects multi-tenancy architecture. The objective behind integrating multi-tenancy aspect in our solution is to give tenants the ability to configure some parts of the application, such as the color of the user interface or business rules, but they can't customize the application's code. This means that although tenants an using the same building blocks in their configuration, the appearance or workflow of the application may be different for two tenants. Also, the Service Level Agreement (SLA) of each tenant can differ. In fact, we contend that multi-tenancy is a requirement for any cloud architecture because of four key benefits. First, High security: there are 3 key components that define the degree of isolation between multiple tenants in a data center: access policies, application deployment and data access and protection. Second, Economy: software development and maintenance costs are shared between the tenants. Third, Service assurance and faster updates: with multi-tenancy, the provider has to make updates once. In contrast with single-tenancy, an architecture in which each customer has their own software instance and may be given access to application code. Fourth, Efficiency and flexibility: A SaaS provider can run one instance of its application on one instance of a database and provide web access to multiple customers. Each tenant's data is Isolated and remains invisible to other tenants [11].

Integrating manufacturing resources planning (MRP II) with flexible manufacturing systems (FMS)

Cost estimation of maintenance phase is necessary to predict the reliability, improve the productivity, project planning, controlling and adaptability of the software. Accurate estimation makes good understanding between the customer and user. Maintenance plays important role in various software developments like Iterative development, Agile development and Component Based Software Development (CBSD). In the recent year, software development turned into engineering through the introduction of Component Based Software Development. Though there are various models to estimate the maintenance cost of traditional software like COCOMO model, SLIM, Function Point (FP) model but till now there is no such model to estimate the maintenance cost of Component Based Software Development. In this kind of situation there is needed to develop a model to estimate the maintenance cost of Component-Based Software (CBS). This paper presents proposed basic maintenance cost estimation model for Component Based Software on the basis of COCOMO. This model is based on three parameters: Development cost of Component Based Software, ACT (Annual Change Traffic), Technical and Non-Technical factors which affect the maintenance cost of Component Based Software.

Scientific missions in the Earth sciences frequently require cost-effective, highly reliable, and easy-to-use software, which can be a challenge for software developers to provide. The NASA Earth Science Enterprise (ESE) spends a significant amount of resources developing software components and other software development artifacts that may also be of value if reused in other projects requiring similar functionality. In general, software reuse is often defined as utilizing existing software artifacts. Software reuse can improve productivity and quality while decreasing the cost of software development, as documented by case studies in the literature. Since large software systems are often the results of the integration of many smaller and sometimes reusable components, ensuring reusability of such software components becomes a necessity. Indeed, designing software components with reusability as a requirement can increase the software reuse potential within a community such as the NASA ESE community. The NASA Earth Science Data Systems (ESDS) Software Reuse Working Group is chartered to oversee the development of a process that will maximize the reuse potential of existing software components while recommending strategies for maximizing the reusability potential of yet-to-be-designed components. As part of this work, two surveys of the Earth science community were conducted. The first was performed in 2004 and distributed among government employees and contractors. A follow-up survey was performed in 2005 and distributed among a wider community, to include members of industry and academia. The surveys were designed to collect information on subjects such as the current software reuse practices of Earth science software developers, why they choose to reuse software, and what perceived barriers prevent them from reusing software. In this paper, we compare the results of these surveys, summarize the observed trends, and discuss the findings. The results are very similar, with the second, larger survey confirming the basic results of the first, smaller survey. The results suggest that reuse of ESE software can drive down the cost and time of system development, increase flexibility and responsiveness of these systems to new technologies and requirements, and increase effective and accountable community participation.

The software that is being developed is becoming more complex and huge. The software industry has a huge problem with software maintenance. During the initial stages of software development, it becomes necessary to identify the ease with which a software system or component can be modified to correct faults, increase performance or adapt to a changing environment, i.e. software maintainability. This aids in the reduction of maintenance costs. A software is developed for some particular purpose, which may or may not change depending on the needs of the customer or the technological process. Hence, it leads to the evolution of the software to fit with the changing requirements. This non-trivial problem requires significant attention. According to some surveys, software maintenance accounts for about 80% of total software development costs. Therefore, this paper proposed a framework to integrate various World Class Manufacturing (WCM)-based technologies to create a model that can be utilized for improving maintenance, reduce time and cost of software maintenance