<title>System performance requirements for a head-tracking autostereoscopic display</title>

This paper discusses two of the six software tools which are being developed as part of the Army Research Institute's MANPRINT Methods development program. The first tool discussed here is known as the System Performance and RAM Constraints Aid or SPARC. This tool permits system designers to determine levels of subfunction performance which are required to achieve function and higher level mission requirements. These levels of subfunction and function performance then serve as requirements which are fed into the second tool, the Manpower Systems Evaluation Aid (MAN-SEVAL). MAN-SEVAL takes as input the system design and then predicts the operator and maintainer manpower required to achieve the required levels of task and function performance. For maintenance manpower evaluation, MAN-SEVAL considers component failure rates, time to perform maintenance, and the mission scenario. For operator manpower and to estimate maintenance task times, MAN-SEVAL conducts an analysis of workload, control/display accessability, and maximum acceptable performance time to allocate tasks across crewmembers. Because all manpower requirements are truly driven by system performance requirements, these two tools are being developed collectively with common data bases and software design. While they are currently being developed for the Army, they will be useful general purpose manpower analysis tools.

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Blind to Chemistry: Molecular Contaminant Films We Could Be Missing During Visual Inspections and the Potential Impact to System Performance

Journal of the IEST ◽

10.17764/1557-2196-63.1.13 ◽

2020 ◽

Vol 63 (1) ◽

pp. 13-20

Author(s):

Elaine Seasly ◽

Walter Wrigglesworth

Keyword(s):

System Performance ◽

Space Mission ◽

Performance Requirements ◽

Mirror Reflectivity ◽

Potential Impact ◽

Contamination Levels ◽

Inspection Techniques ◽

The Impact ◽

Reflectance Measurements ◽

Test Process

Abstract Throughout the assembly, integration, and test process, molecular contamination levels of space mission hardware are monitored to meet system performance requirements. Qualitatively, reflective surfaces and witness mirrors are continuously inspected for the visible presence of molecular contaminant films. Quantitatively, periodic reflectance measurements of witness mirrors indicate changes of mirror reflectivity over time due to the accumulation of molecular contaminant films. However, both methods only consider the presence of a contaminant film and not the molecular composition. Additionally, there is a risk that hardware may appear to be “visibly clean” even with a molecular contaminant film present on critical surfaces. To address these issues, experiments were performed to quantify the maximum molecular contaminant film that could be missed in visual inspections on witness mirrors with five different contaminants present. The corresponding changes in mirror reflectivity were modeled using the program STACK to determine the impact to space mission hardware performance. The results of this study not only show the criticality in considering the chemical make-up of molecular contaminant films on system performance, but also the need to recognize and understand the limitations of traditional visual inspection techniques on detecting molecular contaminant films.

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The Case for Combining Pump Maintenance and Systematic Upgrading

ASME 2008 Power Conference ◽

10.1115/power2008-60065 ◽

2008 ◽

Author(s):

Heinz P. Bloch ◽

Robert Bluse ◽

James Steiger

Keyword(s):

System Performance ◽

Current System ◽

Highly Qualified ◽

Centrifugal Pumps ◽

Term Operation ◽

Performance Requirements ◽

Periodic Maintenance ◽

Work Supports

Virtually, all industrial machinery requires periodic maintenance for dependable long-term operation. In fact, the very term “maintenance” is defined as keeping machines in the as-designed or as-purchased and manufactured condition. At issue is whether the equipment owner’s profitability objectives are best served by “maintaining only”, or by judiciously combining maintenance and upgrading tasks. Assuming the answer favors combining maintenance and upgrading, the question arises whether an intelligent and well thought-out combination of maintenance and upgrading should be entrusted only to the original equipment manufacturer (OEM), or if qualified non-OEMs should be considered also. The co-authors would like to offer their answer to the question. Experience shows that a highly qualified independent rebuild shop with demonstrated capabilities and experienced personnel can offer high-quality upgrades that improve both uptime and efficiency. Such a shop can do so consistent with current system performance requirements. With the considerable consolidations in the pump industry, the distinct possibility exists that the OEM is not able to offer the same engineering competence he previously had and that independent shops should be considered. This presentation deals with a case study and details where such upgrading was being planned, implemented, and verified to have had the desired results. It further explains the role played by competent pump rebuild shops (we chose to call them “CPRS”) in these important endeavors. Our work supports the premise that rebuilding a vintage process pump to original OEM specifications makes no sense, given current pump rebuilding technology and changes to the system performance that occur over time. We find compelling reasons to systematically upgrade the efficiency and potential run length of large centrifugal pumps. Of course, this upgrading must be pre-planned and then carried out during a future maintenance outage.

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Nonfunctional and Domain Requirements

Integrative Document and Content Management ◽

10.4018/978-1-59140-055-4.ch019 ◽

2003 ◽

pp. 415-430

Author(s):

Len Asprey ◽

Michael Middleton

Keyword(s):

Information Technology ◽

System Performance ◽

System Development ◽

Mass Storage ◽

Development Environment ◽

System Administration ◽

Performance Requirements ◽

Operating Environments ◽

Requirements Determination ◽

And Performance

In this chapter, we will examine requirements determination and analysis that may be useful for defining the nonfunctional and domain requirements for an IDCM solution, including system sizing, architecture, and performance requirements. We also include a discussion on domain requirements, such as those for information technology and system administration. Our objectives are to do the following: • Document the requirements for system sizing and mass storage. • Consider the types of requirements analysis that enterprises apply to help suppliers of IDCM solutions offer an architecture solution that may meet enterprise requirements. • Define system performance requirements with known caveats and assumptions. • Define the requirements for the IDCM system to integrate with enterprise desktop, server, and network operating environments. • Define the requirements for the system development environment. • Document the system administration requirements for the system.

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