Problems of Modeling Working Processes in Pneumohydraulic Systems and Units at Various Stages of the Product Life Cycle

2021 ◽  
pp. 60-75
Author(s):  
Y.V. Kyurdzhiev
Keyword(s):  
Life Cycle ◽  
Product Life Cycle ◽  
Dynamic Mode ◽  
Workflow Modeling ◽  
Pressure Regulator ◽  
Modeling Tools ◽  
Product Life ◽  
Current State ◽  
The Moment ◽  
Maintenance Requirements

The article presents the result of the analysis of the problems of maintenance of on-board pneumatic systems and units in terms of the requirements for completeness and efficiency of the requested information. It is shown that the current state of the workflow modeling tools of these systems do not fully meet the maintenance requirements at all stages of the product life cycle. An approach to modeling pneumohydraulic systems and units is proposed, as well as ways to reduce the time from the moment of setting a problem requiring the development of a new mathematical model to obtaining adequate simulation results. The efficiency of the proposed approach is demonstrated by the example of a pressure regulator operating in a dynamic mode. The possibilities and ways of implementing modeling tools based on the proposed approach are shown.

When do megaprojects start and finish? Redefining project lead time for megaproject success

2014 ◽  
Vol 7 (4) ◽  
pp. 624-637 ◽  
Author(s):  
Carlos Eduardo Yamasaki Sato ◽  
Milton de Freitas Chagas Jr
Keyword(s):  
Life Cycle ◽  
Lead Time ◽  
Product Life Cycle ◽  
Product Life ◽  
Content Type ◽  
Operational Life ◽  
Initial Idea ◽  
The Moment ◽  
Project Lead

Purpose – The purpose of this paper is to propose to redefine the concept of project lead time (PLT) to encompass the time between the project initial idea and the moment in which success is being assessed, which can be beyond the project close-out, using whatever criteria is appropriate for the stakeholder at that moment in time. The conventional project life cycle does not count for the long-term effects of the megaproject, which can have a significant impact on its perception of success. Thus the megaproject life cycle should include a significant part of the operational life cycle of the end product or result, and the criteria of success should include the long-term benefits of the project (measured along various years after the delivery of the end product or result). Design/methodology/approach – The paper uses three illustrative cases of megaprojects: Airbus A380, London Heathrow Terminal 5 and London Olympic Games 2012. These megaprojects, despite their problems in achieving objectives of time, cost and quality (the triple constraint), can be viewed as success or failure depending on the performance and benefits of the resulting product/infrastructure analysed over a long period of time after its delivery. Findings – In order to reconcile the usual distinction between project and product life cycle, and the various definitions of success in different moments of the project/product life cycle, the authors propose to redefine the concept of PLT to encompass the time between the project initial idea and the moment in which success is being assessed, beyond the project close-out, using any criteria which is appropriate for the stakeholder at that moment in time. Originality/value – When assessing the success of the megaproject it is important to define the PLT under which success is being assessed. As pointed out earlier, in findings, the authors propose to redefine the concept of PLT to encompass the time between the project initial idea and the moment in which success is being assessed, beyond the project close-out, using any criteria which is appropriate for the stakeholder at that moment in time.

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