The integration of process planning and machine loading in small batch part manufacturing

PART is a highly automated planning system in which both process and production planning functions are integrated. This paper discusses a method to improve machine tool selection in process planning by integration with loading. A method is presented to select the best process plan from a number of possible alternatives taking into account the limited availability of resources. Various aspects of the quality of a process plan are evaluated and expressed in the so-called evaluation time. To prevent redundant work, partly worked out process plans are considered as alternatives. The consequences of the different alternatives have to be estimated which includes the estimation of machining times. The loading problem is modelled as the minimization of the total evaluation time for a given order set, subjected to capacity constraints

Sharing Mobility Data for Planning and Policy Research

A California Public Utilities Commission (CPUC) rulemaking and possible legislative action in 2020 could affect data sharing requirements, with implications for shared mobility providers. The purpose of this brief is to inform this regulatory and legislative decision-making. We solicited policy and planning questions and data needs for shared mobility from within the University of California Institute of Transportation Studies research network. We defined shared mobility as including shared mobility devices, such as e-bikes and e-scooters, and transportation network companies (TNCs). We evaluated whether data shared in accordance with each of six mobility data specifications could be used to support analyses that would answer these questions. We then defined three approaches to data sharing and analysis to address these and other questions, presenting the advantages and disadvantages of each. This brief does not address the full breadth of the questions raised in the CPUC rulemaking nor does it introduce the complexities of this topic. Beyond the scope of this brief are issues of user privacy, the legal authority for sharing data, and contractual or requirements for each possible model of data sharing and analysis

Buffering volatility : storage investments and technology-specific renewable energy support

Mitigating climate change will require integrating large amounts of highly intermittent renewable energy (RE) sources in future electricity markets. Considerable uncertainties exist about the cost and availability of future large-scale storage to alleviate the potential mismatch between demand and supply. This paper examines the suitability of regulatory (public policy) mechanisms for coping with the volatility induced by intermittent RE sources, using a numerical equilibrium model of a future wholesale electricity market. We find that the optimal RE subsidies are technology-specific reflecting the heterogeneous value for system integration. Differentiated RE subsidies reduce the curtailment of excess production, thereby preventing costly investments in energy storage. Using a simple cost-benefit framework, we show that a smart design of RE support policies significantly reduces the level of optimal storage. We further find that the marginal benefits of storage rapidly decrease for short-term (intra-day) storage and are small for long-term (seasonal) storage independent of the storage level. This suggests that storage is not likely to be the limiting factor for decarbonizing the electricity sector

Reliability and Competitive Electricity Markets

Deregulation of the electricity sector has resulted in conflict between the economic aims of creating competitive wholesale and retail markets, and an engineering focus on reliability of supply. The paper starts by deriving the optimal prices and investment program when there are price-insensitive retail consumers, and their load serving entities can choose any level of rationing they prefer contingent on real time prices. It then examines the assumptions required for a competitive wholesale and retail market to achieve this optimal price and investment program. The paper analyses the implications of relaxing several of these assumptions. First, it analyses the interrelationships between regulator-imposed price caps, capacity obligations, and system operator procurement, dispatch and compensation arrangements. It goes on to explore the implications of potential network collapses, the concomitant need for operating reserve requirements and whether market prices will provide incentives for investments consistent with these reserve requirements

Diverse, remote and innovative - Prospects for a globally unique electricity network and market in Western Australia

WA’s electricity industry supply infrastructure comprises the South West Inter-connected System (SWIS), the North West Interconnected System (NWIS) and 29 regional noninterconnected power systems 1. WA exhibits a diversity of generation systems located in some of the most isolated regions of Australia, supplying a wide range of energy demand profiles. These characteristics and the unique networks that comprises WA’s electricity infrastructure makes WA a unique place to research, develop and integrate new technical options within a world-class industrialised electricity system

Diverse, remote and innovative - Prospects for a globally unique electricity network and market in Western Australia

WA’s electricity industry supply infrastructure comprises the South West Inter-connected System (SWIS), the North West Interconnected System (NWIS) and 29 regional non-interconnected power systems 1. WA exhibits a diversity of generation systems located in some of the most isolated regions of Australia, supplying a wide range of energy demand profiles. These characteristics and the unique networks that comprises WA’s electricity infrastructure makes WA a unique place to research, develop and integrate new technical options within a world-class industrialised electricity system