Question 1: Top down considerations in establishing a shutdown schedule for a complex system
When decomposing/shutting down a complex system, there guidelines or considerations that should be adhered to (Kossiako & Sweet, 2013). It is important to note that the top down shutdown process’ first level decomposes the system in chunks or major functions or major systems. For every section, the individual section is shutdown in even smaller divisions. This forms the second stage or level of the shutdown process. The process continues giving smaller divisions at every level the entire process becomes the top down shutdown process (Kossiako & Sweet, 2013). Consideration of top down shutdown process of a complex system has a number of considerations (Kossiako & Sweet, 2013). These considerations lie under three shutdown processes: Assembly shutdown, functional shutdown and service based shutdown (Kossiako & Sweet, 2013).
Under assembly shutdown, one of the aspects to be considered is familiarity of the system (Kossiako & Sweet, 2013). A visual inspection should be carried out to ensure that the system is totally familiar to the operators. Thereafter, identification of sub-assemblies to taken out of the system should be looked considered (Kossiako & Sweet, 2013). Immediately after identification of these sub-assemblies, the big chunks are removed (Kossiako & Sweet, 2013). Removal of the chunk is simply done by breaking down the chunks in the system to make them smaller. Once these subassemblies have been recorded into the DSM, the first stage of the process comes to the end (Kossiako & Sweet, 2013). Even so, at this level of decomposition process, controls, drives, electrical components and air systems must be maintained in an intact form. Thereafter, the second level of the process is started: Functional shutdown (Ben-Daya & Raouf, 1995).
During functional shutdown, the system is simplified further through its main function. Similar to the assembly level of the system shutdown, the level has its own considerations. The first consideration is self-controlled sub-system. Self-controlled sub-system is considered because it is supposed to be divided into smaller subdivisions. Thereafter, material, signal connections and energy is identified and looked into. Just as above, the information is again recorded into the DSM. Thus filling of DSM with various disciplines with their respective connections. The disciplines present are considered because they are to be broken into the subsystem in order to bring the second level of system shut down into completion (Labib, 2003).
Service based shutdown has some considerations too. First is the representation of assembly shutdown level of complex level shutdown process. This is because at service based level, the assembly level of the complex system shutdown process is represented on the high system level; the representation is on each chapter (Ben-Daya & Raouf, 1995). As usual, DSM has to be considered; including chapters and connections. Thereafter, the chapters are re-divided into smaller divisions forming sub sections. This breakdown continues until the system is shutdown; which happens after the system has been reduced to a component. Hence the name, top-down approach (Kossiako & Sweet, 2013).
Last but not least, the duration of the preventive task maintenance task should be predetermined. Additionally, during the inspection process, the supervision should ensure that exact time or less while ensuring maximum value is derived in the course of that time. Besides, the inter-inspection time should be determined. Putting in place efficient and sufficient supervision continuously during the preventive maintenance process ensures that allocation time is used effectively; making resources used to be commensurate to the value gained from the process and the work is completed with great success.
Question 2: Considerations in determining an optimum grouping for proposed preventive maintenance tasks
Understanding what preventive maintenance of a task is, is key to understanding what you need to consider while designing optimum grouping for proposed maintenance tasks (LCE, 2010). Preventive maintenance refers to a systematic maintenance of equipment that ensures continuous operation of equipment; the maintenance is done based on a routine and is usually regular (LCE, 2010). For a successful preventive maintenance task to be carried out, a carefully designed plan should be implemented and clear records of previous inspection be kept to ensure consistence and success of the future maintenance. Besides, strategic approach to this kind of maintenance task ensures that the equipment do not break down before next maintenance task (LCE, 2010).
For one to have an optimum grouping for preventive maintenance task, one should consider value-addition (LCE, 2010). What does value the preventive maintenance task performed add to the asset of the business? It is a very important question for every concerned part to ask him/herself. The measures put in place to prevent system breakdown, which is the core objective of preventive maintenance task, should consider what value the inspection adds to the system against the cost incurred. If the cost is higher than the value the maintenance brings into the system then the process should be shunned. An optimum grouping of a preventive maintenance shoulder strike a balance between the benefits vis-à-vis the cost (LCE, 2010).
The second factor to be considered is comprehension. The preventive maintenance is should be comprehensive (LCE, 2010). The preventive maintenance carried out should be seen and measured. The PM-Preventive Maintenance, should take into consideration and include periodic calibration of critical elements to ensure that the whole system is more of perfect calibration. Besides inclusion of clear calibrations, periodic adjustments of various elements such as belts, belt tension, clearances and power transmission should be considered and included. Another important additionally, periodic adjustments should take into considerations components such as belts and gaskets which are main components of many systems (LCE, 2010).
Question 3: Important things to consider in publishing inspection task descriptions for preventive maintenance
Inspection task description is a detailed explanation or statement of the work that will accompany an inspection task in maintenance process (Lauesen, 2001). Consequently, a clear and detailed statement should be given to ensure work to be one is understood.
Consequently, the first consideration when publishing the inspection task description for preventive maintenance is purpose. The publisher should clearly know what exactly the task is supposed to achieve. In technical language, the publisher should know the check-in’s purpose. Check-in’s purpose is called goal and post condition of an inspection (Lauesen, 2001).
Besides, during publishing of task description, subtasks should be taken into consideration (Lauesen, 2001). Subtasks specify what exactly is to be done during the implantation of the inspection process. In fact, subtask are at the core of task implementation as they give the specificities of the work to be done. Thus the publisher should ensure that all subtasks are clearly and elaborately explained in the description (Lauesen, 2001).
Other important considerations are subtask variants and sequence. The sequence of the subtasks should be clearly stated and their respective requirements outlined. The same applies to the subtask variants (Lauesen, 2001).
Ben-Daya, M., & Raouf, A. (1995). Total maintenance management: a systematic approach. Journal of Quality in Maintenance Engineering, 6-14.
Kossiako, A., & Sweet, W. (2013). System Engineering Principles and Practice.
Hoboken: NJ. Labib, A. (2003). Maintenance strategies: a systematic Approach for selection of the right strategies. Springer Link, 336-349.
Lauesen, S. (2001, July 4). Task Descriptions asFunctional Requirements. Retrieved from Unversity of Coopenhage: https://citeseerx.ist.psu.edu/viewdoc/download?
LCE. (2010). What Do Your Preventive Maintenance Tasks Really Do For Your Asset Care Strategy? Retrieved from Life Cycle Engineering: https://www.lce.com/WhatDo- Your-Preventive-Maintenance-Tasks-Really-Do-For-Your-Asset-Care-Strategy- 1205.html