scholarly journals A Hybrid Personnel Scheduling Model for Staff Rostering Problems

Mathematics ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1702
Author(s):  
Jiun-Yan Shiau ◽  
Ming-Kung Huang ◽  
Chu-Yi Huang
Keyword(s):  
Airline Industry ◽  
Real Life ◽  
Integrated Approach ◽  
Manpower Planning ◽  
Mixed Integer ◽  
Aviation Industry ◽  
Personnel Scheduling ◽  
Staff Scheduling ◽  
Mip Model

The problem of staff scheduling in the airline industry is extensively investigated in operational research studies because efficient staff employment can drastically reduce the operational costs of airline companies. Considering the flight schedule of an airline company, staff scheduling is the process of assigning all necessary staff members in such a way that the airline can operate all its flights and construct a roster line for each employee while minimizing the corresponding overall costs for the personnel. This research uses a rostering case study of the ground staff in the aviation industry as an example to illustrate the application of integrating monthly and daily schedules. The ground staff in the aviation industry case is a rostering problem that includes three different types of personnel scheduling results: fluctuation-centered, mobility-centered, and project-centered planning. This paper presents an integrated mixed integer programming (MIP) model for determining the manpower requirements and related personnel shift designs for the ground staff at the airline to minimize manpower costs. The aim of this study is to complete the planning of the monthly and daily schedules simultaneously. A case study based on real-life data shows that this model is useful for the manpower planning of ground services at the airline and that the integrated approach is superior to the traditional two-stage approach.

Cathay & Southwest: flying the flag of good practice in airline mergers

2015 ◽  
Vol 31 (8) ◽  
pp. 20-22 ◽  
Author(s):  
Reetesh Sharma ◽  
Mark Thomas
Keyword(s):  
Airline Industry ◽  
Large Scale ◽  
Good Practice ◽  
Aviation Industry ◽  
Content Type ◽  
Key Stakeholders ◽  
The Usa ◽  
Airline Mergers ◽  
Southwest Airlines

Purpose – This article highlights the essential factors to be considered for successful mergers and acquisitions (M & As) in the aviation industry. The article draws insights from the successful deals between Morris and Southwest Airlines as well as Cathay Pacific and Dragonair. Design/methodology/approach – The article is a case study of two successful mergers in the airline industry, one in the USA and one in Asia. Findings – M & As in the airline industry are loaded with difficulties. These include problems of brand identification, opposition from key stakeholders and the need of forming one coherent organisational culture. However, this does not mean that they are impossible. Two large-scale mergers have shown that successful mergers can occur in the industry. Originality/value – This article gives examples of two successful M & A deals from the aviation industry and shows the important factors to achieve this.

scholarly journals Fuel Gas Network Synthesis Using Block Superstructure

2018 ◽  
Author(s):  
Jianping Li ◽  
Salih Emre Demirel ◽  
M. M. Faruque Hasan
Keyword(s):  
Process Design ◽  
Real Life ◽  
Mixed Integer ◽  
Network Synthesis ◽  
Systematic Method ◽  
Fuel Gas ◽  
Gas Network ◽  
Classical Source ◽  
Minlp Problem

Fuel gas network (FGN) synthesis is a systematic method for reducing fresh fuel consumption in a chemical plant. In this work, we address the synthesis of fuel gas network using block superstructure originally proposed for process design and intensification (Demirel et.al. [1]). Instead of a classical source-pool-sink superstructure, we consider a superstructure with multiple feed and product streams. These blocks interact with each other through direct flows that connect a block with its adjacent blocks and through jump flows that connect a block with all blocks. The blocks with feed streams are viewed as fuel sources and the blocks with product streams are regarded as fuel sinks. Addition blocks can be added as pools when there exists intermediate operations among 9 source blocks and sink blocks. These blocks can be arranged in a I × J two-dimensional grid with I = 1 for problems without pools, or I = 2 for problems with pools. J is determined by the maximum number of pools/sinks. With this representation, we formulate fuel gas network synthesis problem as a mixed-integer nonlinear (MINLP) problem to optimally design a fuel gas network with minimal total annul cost. We present a real-life case study from LNG plant to demonstrate the capability of the proposed approach.

Reconfiguration of assembly line balancing–an automobile case study solved by the exact solution procedure

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ashish Yadav ◽  
Shashank Kumar ◽  
Sunil Agrawal
Keyword(s):  
Cycle Time ◽  
Assembly Line ◽  
Real Life ◽  
Assembly Line Balancing ◽  
Line Balancing ◽  
Mixed Integer ◽  
Second Step ◽  
Automobile Plant ◽  
Content Type

PurposeMulti-manned assembly lines are designed to produce large-sized products, such as automobiles. In this paper, a multi-manned assembly line balancing problem (MALBP) is addressed in which a group of workers simultaneously performs different tasks on a workstation. The key idea in this work is to improve the workstation efficiency and worker efficiency of an automobile plant by minimizing the number of workstations, the number of workers, and the cycle time of the MALBP.Design/methodology/approachA mixed-integer programming formulation for the problem is proposed. The proposed model is solved with benchmark test problems mentioned in research papers. The automobile case study problem is solved in three steps. In the first step, the authors find the task time of all major tasks. The problem is solved in the second step with the objective of minimizing the cycle time for the sub-tasks and major tasks, respectively. In the third step, the output results obtained from the second step are used to minimize the number of workstations using Lingo 16 solver.FindingsThe experimental results of the automobile case study show that there is a large improvement in workstation efficiency and worker efficiency of the plant in terms of reduction in the number of workstations and workers; the number of workstations reduced by 24% with a cycle time of 240 s. The reduced number of workstations led to a reduction in the number of workers (32% reduction) working on that assembly line.Practical implicationsFor assembly line practitioners, the results of the study can be beneficial where the manufacturer is required to increased workstation efficiency and worker efficiency and reduce resource requirement and save space for assembling the products.Originality/valueThis paper is the first to apply a multi-manned assembly line balancing approach in real life problem by considering the case study of an automobile plant.

scholarly journals Operating Room Scheduling in Teaching Hospitals

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Somayeh Ghazalbash ◽  
Mohammad Mehdi Sepehri ◽  
Pejman Shadpour ◽  
Arezoo Atighehchian
Keyword(s):  
Operating Room ◽  
Real Life ◽  
Operating Rooms ◽  
Mixed Integer ◽  
Teaching Hospitals ◽  
Operating Room Scheduling ◽  
Start Time ◽  
The Real ◽  
Mip Model ◽  
Proposed Model

Operating room scheduling is an important operational problem in most hospitals. In this paper, a novel mixed integer programming (MIP) model is presented for minimizing Cmax and operating room idle times in hospitals. Using this model, we can determine the allocation of resources including operating rooms, surgeons, and assistant surgeons to surgeries, moreover the sequence of surgeries within operating rooms and the start time of them. The main features of the model will include the chronologic curriculum plan for training residents and the real-life constraints to be observed in teaching hospitals. The proposed model is evaluated against some real-life problems, by comparing the schedule obtained from the model and the one currently developed by the hospital staff. Numerical results indicate the efficiency of the proposed model compared to the real-life hospital scheduling, and the gap evaluations for the instances show that the results are generally satisfactory.

scholarly journals Mixed Integer Linear Programming Models to Solve a Real-Life Vehicle Routing Problem with Pickup and Delivery

2021 ◽  
Vol 11 (20) ◽  
pp. 9551
Author(s):  
Ali Louati ◽  
Rahma Lahyani ◽  
Abdulaziz Aldaej ◽  
Racem Mellouli ◽  
Muneer Nusir
Keyword(s):  
Linear Programming ◽  
Vehicle Routing ◽  
Integer Linear Programming ◽  
Vehicle Routing Problem ◽  
Mixed Integer Linear Programming ◽  
Real Life ◽  
Mixed Integer ◽  
Pickup And Delivery ◽  
Routing Problem

This paper presents multiple readings to solve a vehicle routing problem with pickup and delivery (VRPPD) based on a real-life case study. Compared to theoretical problems, real-life ones are more difficult to address due to their richness and complexity. To handle multiple points of view in modeling our problem, we developed three different Mixed Integer Linear Programming (MILP) models, where each model covers particular constraints. The suggested models are designed for a mega poultry company in Tunisia, called CHAHIA. Our mission was to develop a prototype for CHAHIA that helps decision-makers find the best path for simultaneously delivering the company’s products and collecting the empty boxes. Based on data provided by CHAHIA, we conducted computational experiments, which have shown interesting and promising results.

scholarly journals An integrated approach to teaching and learning logistics: A case study

2011 ◽  
Vol 5 (1) ◽  
Author(s):  
Jacobus N. Cronjé
Keyword(s):  
Teaching And Learning ◽  
Real Life ◽  
Integrated Approach ◽  
Project Based Learning ◽  
University Teaching ◽  
Research Skills ◽  
Theoretical Concepts ◽  
Life Project ◽  
Approach To Teaching

Business managers and students often criticise university teaching for not addressing real-life problems. Furthermore, professors are dissatisfied with the research capabilities of postgraduate students. This paper advocates an integrated approach to teaching and learning based on the features of project-based learning aimed at enhancing the practical and research skills of undergraduate students in Logistics. A case study is presented where third-year students were engaged in a real-life project in collaboration with industry, exposing them to collaborative learning, questionnaire design, surveys, analysing and evaluating results, literature review and report writing. The project was carried out in phases where students were assessed after each phase. The paper analyses the assessment of students and their perception of the value of the project. It is concluded that an integrated teaching and learning approach will increase students’ interest in the subject, understanding of theoretical concepts, research skills, business skills and life skills.

scholarly journals Home care vehicle routing problem with chargeable overtime and strict and soft preference matching

2021 ◽  
Author(s):  
Laura Malagodi ◽  
Ettore Lanzarone ◽  
Andrea Matta
Keyword(s):  
Home Care ◽  
Continuity Of Care ◽  
Vehicle Routing Problem ◽  
Linear Problem ◽  
Real Life ◽  
Mixed Integer ◽  
Routing Problem ◽  
Decomposition Approach ◽  
The Usa

AbstractA new scheduling problem arising in the home care context is addressed, whose novelty with respect to the literature lies in the way overtime is paid. In this problem, some clients are willing to pay a higher fee to cover the additional overtime cost, if such overtime is incurred because a caregiver works extra time with the client to preserve continuity of care. These overtime hours charged to clients unburden the company, which no longer has to balance between cost and continuity of care in a traditional way. The problem is also studied in a context that includes preferences expressed by both clients and caregivers. Strict preferences must be respected with a high priority, while soft preferences increase the satisfaction and should be preferably respected. We formalize the problem as a Mixed Integer Linear Problem and also propose a cluster-based decomposition to solve real-life instances. The problem is inspired by the real case study of a provider operating in the USA. Numerical results validate the model and confirm the capability of the decomposition approach to deal with real-life instances.

scholarly journals Automated Generation of Schematic Network Maps with Preservation of Main Structures

2019 ◽  
Vol 1 ◽  
pp. 1-2
Author(s):  
Tian Lan ◽  
Zhilin Li
Keyword(s):  
Real Life ◽  
Route Planning ◽  
Human Cognition ◽  
Mixed Integer ◽  
Global Features ◽  
Main Structure ◽  
Whole Process ◽  
Automated Method ◽  
Mip Model ◽  
Automated Methods

<p><strong>Abstract.</strong> Schematic (network) maps are helpful for people to perform route planning and orientation tasks. The London Underground Map designed by Harry Beck is an excellent example of such maps. Generally, there are three approaches to generate schematic maps: manual, semi-automated (or computer-aided) and fully automated. In the past twenty years, many researchers have been devoted to the development of automated methods for generation of schematic maps. In these automated methods, various sets of constraints are used. Most of these constraints are for geometric properties of individual features (such as the lengths and orientations of lines); a few constraints are for relations between features (such as the minimum distance threshold between non-incident edges); but none are explicitly for the main structures of whole networks. It is believed that preservation of the main structure is the most important, because main structure is represented by global features which is first recognized by a pre-attentive process in human cognition – a global-to-local process (in which local features are then recognized by an attentive process). It is hypothesized here that an automated method with the preservation of main structures of networks should be able to generate schematic maps with improved clarity and aesthetics.</p><p>This paper describes the development of an automated method with the preservation of the main structures of line networks. In this method, automated schematization is treated as an optimization problem and is represented as a Mixed-Integer Programming (MIP) model, which consists of an objective function and a set of constraints. The preservation of main structures is modelled into constraints (i.e., making important lines straight and orientating them to specific directions) for the model. The MIP model is imported into a commercial optimization software called “IBM ILOG CPLEX Optimization Studio” (version 12.6.3) for the acquisition of optimal solutions (i.e., coordinates of vertices and edges on schematic maps). The whole process is shown in Figure 1.</p><p>Experimental evaluations have been conducted with a set of real-life data as shown in Figure 2a and 2d. Schematic maps are generated by this new method with the preservation of main structures and by an old method without the particular consideration for main structures, as shown in Figures 2b, 2c, 2e and 2f. A psychological test with a questionnaire has been conducted, which consists of questions regarding “clarity”, “recognition of major lines”, “visual simplicity” and “satisfaction”. It is found that, in all these four aspects, the map generated by new methods with preservation of main structures have higher scores than those by the old method. These improvements are proved to be significant after paired-t tests.</p><p>Therefore, it is concluded that the new automated method with the preservation of main structures can generate schematic maps with significant improvement in clarity and aesthetics. This study is helpful to improve automated methods for generation of schematic maps and other visual representations.</p>

A mixed integer programming model to evaluate integrating strategies in the forest value chain — a case study in the Chilean forest industry

2015 ◽  
Vol 45 (7) ◽  
pp. 937-949 ◽  
Author(s):  
Juan Troncoso ◽  
Sophie D’Amours ◽  
Patrik Flisberg ◽  
Mikael Rönnqvist ◽  
Andrés Weintraub
Keyword(s):  
Integer Programming ◽  
Mixed Integer Programming ◽  
Value Chain ◽  
Planning Horizon ◽  
Integrated Approach ◽  
Mixed Integer ◽  
Forest Industry ◽  
Business Planning ◽  
Mip Model ◽  
Integrated Strategy

When a company is integrated vertically, it can manage and plan its overall value chain in one direct and integrated approach. However in many cases, companies follow a decoupled approach where forests and production plants optimize separately their processes in a supply-driven strategy. In Chile, the two largest forest companies are vertically integrated (i.e., they own forest and mills that produce logs, lumber, plywood, pulp, paper, and bioenergy, etc.). Historically, they have coordinated their value chains using a make-to-stock strategy, for which the forest is the main driver of the value chain activities. In this paper, we propose an integrated planning approach to show the impacts of a demand-driven integration of the value chain in the forest industry. To compare this strategy with the decoupled strategy, we propose a mixed integer programming (MIP) model for the integrated strategy. To illustrate our proposal, we use forest and production information from a Chilean forest company. The decoupled strategy, where the forest and industry planning are planned separately, uses two models. The first model deals with the forest management and harvesting decisions and maximizes the expected net present value (NPV) of logs. In this model, the planning horizon covers one full forest rotation, which in Chile corresponds to about 25 years. The second model maximizes the NPV of the downstream operations for a shorter business planning horizon (five years) constrained by the availability of the logs from the first model. In the integrated approach, all parts of the value chain (forest, transportation, and mills) are driven by final product demand and where the objective is to maximize the profit of the company (NPV of the entire value chain). The demand is only given for the shorter business planning horizon. The two strategies are evaluated using the MIP model, and NPV is used to determine the best practice. According to the results, the NPV can increase up to 5.0% when the proposed integrated strategy is implemented compared to a decoupled strategy. Moreover, the profit for the business period increases up to 8.5%.

Contamination Lab of Turin (CLabTo)

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Eleonora FIORE ◽  
Giuliano SANSONE ◽  
Chiara Lorenza REMONDINO ◽  
Paolo Marco TAMBORRINI
Keyword(s):  
University Students ◽  
Single Case ◽  
Real Life ◽  
Learning By Doing ◽  
Assessment Data ◽  
Entrepreneurial Skills ◽  
Fields Of Study ◽  
Education Levels ◽  
Positive Effect

Interest in offering Entrepreneurship Education (EE) to all kinds of university students is increasing. Therefore, universities are increasing the number of entrepreneurship courses intended for students from different fields of study and with different education levels. Through a single case study of the Contamination Lab of Turin (CLabTo), we suggest how EE may be taught to all kinds of university students. We have combined design methods with EE to create a practical-oriented entrepreneurship course which allows students to work in transdisciplinary teams through a learning-by-doing approach on real-life projects. Professors from different departments have been included to create a multidisciplinary environment. We have drawn on programme assessment data, including pre- and post-surveys. Overall, we have found a positive effect of the programme on the students’ entrepreneurial skills. However, when the data was broken down according to the students’ fields of study and education levels, mixed results emerged.

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