Attachment 0009 - R and M Prediction Report.docx

Integrated Air and Missile Defense (IAMD) Battle Command System (IBCS) Reliability, Availability and Maintainability (RAM) Predictions and Analysis

Systems Engineering & Integration Document

This material is based upon work supported by the U.S. Army Aviation and Missile Command under Contract No. W31P4Q-08-C-0418.

Integrated Air and Missile Defense (IAMD) Battle Command System (IBCS) Northrop Grumman Mission Systems Missile Defense and Protective Systems Division

213 Wynn Drive

Huntsville, AL 35805

CAGE Code 9F909

Integrated Air and Missile Defense (IAMD) Battle Command System (IBCS)

Reliability, Availability and Maintainability (RAM) Predictions and Analysis Approval Sheet

SIGNATURES FOR RELEASE:

Andrew Sutinen, IBCS Reliability Engineering Lead

Date

Daiven Harper, IBCS Specialty Engineering Lead

Date

Mike Myszka, IBCS SE&I IPT Manager

Date

Lori Tatom, IBCS Mission Assurance Manager

Date

Mark Rist, IBCS Program Director

Date

Kristi Fugit, IBCS Configuration/Data Management

Date

Document Type:

Systems Engineering & Integration

Notes or Comment:

N/A

Northrop Grumman Mission Systems Missile Defense and Protective Systems Division IAMD Battle Command System (IBCS) 213 Wynn Drive Huntsville, Alabama 35805-1928

CHANGE RECORD

Release Number

Date

27 Feb 2019 2 Aug 2019

SOW

SOW

All All DCR-6089, Initial Release DCR-6160, Resubmittal Due to Rejection

1 Nov. 2019

Copyright 2020 Northrop Grumman Systems Corporation.

UNCLASSIFIED-For Official Use Only i IBCS.DM.025.24 (Jan16)

Copyright © 2020 Northrop Grumman Systems Corporation.

UNCLASSIFIED-For Official Use Only ii IBCS.DM.025.24 (Jan16)

Table of Contents

List of Figures

List of Tables

Introduction This section provides the purpose and scope of the S-280 Prototype Shelter Variant for the Integrated Air and Missile Defense (IAMD) Battle Command System (IBCS) Reliability Block Diagrams and Mathematical Modeling Report, as well as provides a document and program overview.

Purpose This IBCS Reliability Block Diagrams and Mathematical Modeling Report documents the approaches, procedures, and data used to determine mission reliability parameters used for allocation, predictions, assessments, and design analyses for IBCS. This report also documents the IBCS reliability and maintainability allocations and predictions current at the time of the release of this Contract Data Requirements List (CDRL). The predictions are expected to continue to change in the near future due to design updates and better understanding of the hardware and software and how they affect the behavior of IBCS. However, it is important to continually track these parameters to ensure that the design is on track to meeting its requirements and user expectations. This analysis will be updated accordingly to reflect the most current design as changes are made throughout the development process and will be presented to the customer on a biannual basis.

Scope This report applies to all IBCS S-280 Shelter mission hardware and will be used during the design phase to analyze the hardware design and any modifications thereafter. The report applies to IBCS S-280 Shelter (also known as S-280 Engagement Operation Center). This IBCS report is developed as CDRL IBCS-A241, uses MIL-HDBK-217F, MIL-HDBK-470A, and MIL-HDBK-472 as guides, and is updated once at the end of the performance period.

This report revision addresses updates to the following sections:

· Section 4.7 Mean Time between Failure Critical (MTBFc) Traceability: Allocations for reliability and maintainability parameters below the EOC and IFCN Relay. EOC and IFCN Relay Hardware LRUs built to specifications and have reliability requirements are included.

· Section 4.7. MTBFc Traceability: Software Reliability Prediction basis is predicated on V4.5 ER2 and V4.5 RR IAMD Test Events Hours and associated scored Essential Failure Functions.

· Section 4.7. MTBFc Traceability: Predicted Reliability Vendor Failure Rates have been updated and documented in the Hardware FMECA CDRL A243-002 and are utilized to update the EOC and IFCN Relay Reliability Predictions.

· Section 4.9. Mean Time To Repair (MTTR): Maintainability predictions and analysis is based on the Level of Repair Analysis (LORA) results which in turn utilizes time tasks from the Maintenance Allocation Chart CDRL A296-006. MTTR has been updated with new task time estimates for Inspection, Fault Detection, Fault Isolation, Disassembly, Remove and Repair, Adjustments, Checkouts, and Verification

· Section 4.10. IBCS Testability Concept Using Continuous Built In Test (CBIT): Maintenance Testability Analysis Updated with percentage detection from the updated Hardware FMECA CDRL A243-002 that includes the EOC and Relay LRU CBIT/User Observations. CBIT Per Cent Detection, Isolation, and summary are presented.

Document Overview Section 1: Introduction: Describes purpose, scope, and updates, and provides document and program overviews Section 2: Applicable Documents: List reference documents, standards, and handbooks related to this plan Section 3: System Overview: Provides a description of IBCS and the major items from a reliability modeling perspective Section 4: RAM Modeling: Outlines how the allocation and prediction analyses are performed Section 5: RAM Analysis Results: Summarizes the results of the allocation and prediction analyses Section 6: Abbreviations and Acronyms: Lists abbreviations and acronyms used in this document Appendix A: Associated Commercial and Government Entities (CAGE) Appendix B: A241 Relay and EOC LRU Reliability Predictions Appendix C: IBCS System Reliability Block Diagram Appendix D: IBCS EOC and Relay Fault Tree Analysis (FTA) IBCS Program Overview The Army Integrated Air and Missile Defense (AIAMD) System of Systems (ASoS) integrates current and future sensors, weapons, and their respective Command and Control (C2) into a networked Air and Missile Defense (AMD) system. The materiel solution for the ASoS C2 is the IAMD Battle Command System (IBCS).

IBCS provides the net-centric, Plug and Fight (P&F), System of Systems (SoS) Command, Control, and Communications, Computers, Intelligence, Surveillance, and Reconnaissance (C4ISR) capability of the IAMD architecture. IBCS consists of two Major End Items (MEIs): the Engagement Operations Center (EOC) and the IBCS Integrated Fire Control Network (IFCN) Relay. The IBCS EOC provides C4ISR functions at battalion (BN) and battery (BTRY) echelons within the AMD Task Force (TF). Both the IBCS EOC and the IBCS IFCN Relay have a P&F B-Kit that enables IAMD weapon and sensor components to fight in the net-centric ASoS. Components to be integrated on the IFCN develop an A-Kit to connect to the IBCS B-Kit. The A-Kit provides the component specific details needed to adapt the sensor or weapon to the A/B Interface specification. Northrop Grumman produces the IBCS EOC and the IBCS IFCN Relay which draw from a set of common software modules that provide track management, engagement operations, interface services (both human and machine), planning, training and supporting software infrastructural needs. IAMD weapon and sensor program offices provide the unique hardware and software items used for integration of their system’s A-Kit with the B-Kit. In addition, Northrop Grumman is developing the IFCN that integrates IBCS MEIs and ASoS-enabled sensors and weapons into a cohesive, network-centric task force.

The OV1- High Level Operational Concept, as defined by the Training and Doctrine Command (TRADOC) Capability Manager (TCM), is shown in Figure 1‑1, and includes IBCS, Lower Tier Project Office (LTPO) sensors and weapons, Cruise Missile Defense Systems (CMDS) Project Office sensors and weapons, as well as the IFCN.

Figure 1‑1. OV1- High Level Operational Concept

The IBCS architecture enhances the Warfighter’s ability to execute AMD battle command. By modernizing command and control, the kinematic capabilities of all weapons and detection and tracking envelopes of all sensors can be fully utilized. By establishing and invoking the common standards sought by the Joint IAMD, the vision of a truly joint IAMD is realized. This innovative approach at modernization reduces manpower, enhances training, and reduces operation and support cost while at the same time providing a more robust and effective AMD.

Applicable and Analysis Software The documents listed in this section form a part of this report to the extent specified herein.

Government Documents Table 2-1 lists Government documents relevant to the reliability modeling and analysis effort.

Table 2‑1. Government Reference Documents

MIL-HDBK-217F N2

Notice 2: Feb, 1995 Reliability Prediction for Electronic Equipment

MIL-HDBK-338B

Notice 2: May 2012 Electronic Reliability Design Handbook

MIL-HDBK-470A

Notice 2:May, 2012 Designing and Developing Maintainable Products and Systems, Volume 1

MIL-HDBK-472,

Notice 1: Jan, 1984 Maintainability Predictions

MIL-STD-756B

19 Nov 1983 Reliability Modeling and Prediction

MIL-M-24100C (Notice 1) 20 Jul 1995 Military Specification: Manuals, Technical: Functionally Oriented Maintenance Manuals (Form) For Electronic, Electromechanical, And Ordnance Equipment, Systems, and Platforms

Northrop Grumman Documents Table 2-2 lists documents generated by Northrop Grumman or other team members used in development of this report.

Table 2‑2. Northrop Grumman Documents

Table 2‑3. Prediction and Analysis Tools

System Overview The IBCS capability includes the IBCS EOC, IFCN Relays, and the IFCN. All three components are tied together and driven by the IBCS software. The IBCS architecture enables IBCS EOCs capable of supporting operations at echelons Platoon through Battalion IAMD TF connected via the IFCN to sensor and weapons through IFCN Relays which provide the means to interoperate with existing sensors and weapons.

S-280 EOC

IBCS S-280 EOCs are configurable facilities used by IAMD ASoS commanders and staffs to control AMD forces. Each will contain a similar capability tailored to the mission requirements of each respective echelon. The configurations of the EOC at each echelon are scaled to match required capabilities both in size and capability. The IBCS EOC consists of a standard Army prime mover (Family of Mobile Tactical Vehicles [FMTV] M1148), S-280 shelter with IFCN communications equipment, and trailer containing a tactical generator, deployable IBCS Collaboration Environment (ICE) tent, ICE Environmental Control Unit (ECU) ICE primary operational components, and ancillary support equipment. Additionally, the IBCS EOC will use Non-Developmental-Item (NDI), COTS, Government-furnished equipment (GFE), and developed Common Software Modules (CSMs) within EOC software builds. The IBCS EOC design maximizes commonality across BN, BTRY, and Platoon echelons.

IBCS uses a common vehicle and shelter as the EOC for all echelons to maximize commonality. IBCS EOC hardware design maximizes the use of the Army’s Standardized Integrated Command Post System (SICPS) HDT Small Tactical Air Beam Tent (STAT, model 2021). It uses the GFE Army standard trailer (M1061A1P2) to carry a 3.3 kW generator, ECU, and ICE. The FMTV (shown in Figure 3-1 with IBCS EOC components) replaced the originally selected prime mover due to availability of the vehicle.

The EOC Prime Mover subsystem includes Joint Battle Command Platform (JBC-P) (incorporating updated Force XXI Battle Command Brigade and Below (FBCB2) Joint Capabilities Release (JCR) and Blue Force Tracker 2 (BFT) capabilities) in the FMTV M1148 cab and auxiliary power generator, cabling, breakout boxes and work platforms externally.

Figure 3‑1. FMTV with IBCS S-280 EOC and Trailer Family of Mobile Tactical Vehicles (FMTV) The M1148 is a 6x6 wheeled vehicle with a long wheelbase. The IBCS design will utilize the vehicle chassis for mounting the S-280 EOC shelter on a Container Roll-On/Off Platform (CROP).

The FMTV includes an armor-ready cab with seating for a driver and two passengers. The cab can be upgraded with additional bolt-on armor for increased crew protection. The turbocharged diesel engine produces 330 hp (246 kW), and the fuel system includes a 56 gal (212 L) capacity fuel tank. The overall length is 29 ft 4 in. (8.9 m), overall width is 8 ft. (2.4 m), and overall height is 9 ft. 4 in. (2.8 m). The curb weight is 26,041 lbs. (11,812 kg) without IBCS components installed. The maximum operating speed without the bolt-on armor or installation of IBCS components is 55 miles per hour.

IBCS S-280 EOC Shelter The S-280 EOC Shelter, as shown in Figures 3-3, and Figure 3-4, is the basic building block for IBCS EOCs.

Figure 3‑2. IBCS S-280 EOC Shelter Curbside View

Figure 3‑3. IBCS S-280 EOC Shelter Exterior Isometric View

The IBCS S-280 EOC is rapidly-deployable with two operator stations to establish minimum functionality while the ICE is being deployed and maintain minimum functionality should the ICE be unavailable.

The EOC is common at all echelons and host multiple IBCS, battle command and combat service support software suites, and communications equipment, and interface with numerous non-battle command vehicles to serve as an information aggregation point. The common shelter includes rack designs and cabling for installation compatibility of all required IBCS radios. The common cable infrastructure based on the S280 product line provides common interfaces for data, power, radio frequency (RF), and audio connections in every EOC. The IBCS S280 EOC development will be an extension of the Northrop Grumman existing Command Post Platform (CPP) hardware product line.

The key feature and primary assembly of the EOC shelter is the C2 Assembly, a common suite of electronics. The C2 Assembly consists of a computer/server system, a networking system connecting to the IFCN, a communication system which includes provisions for mounting radios, and the Command Post Communication System (CPCS) Tactical Operations Communications Network (TOCNET). The common C2 Assembly eliminates unique parts at each IBCS echelon, reduces the training burden on Soldiers, ensures commonality, and reduces the logistics burden on units. The Tent Interface Panel (TIP) provides NIPR/SIPR fiber connections to the ICE workspace, and the Signal Entry Panel (SEP) provides for fiber connections to A-side interfaces and alternate media. The EOC Shelter contains the common HNR components.

ICE

The ICE consists of self-contained STAT (Small Tactical Air Beam Tent) in which to conduct battle command at the halt. The STAT systems are quickly erectable, electromagnetic interference (EMI)-protected, and designed to be standalone or connected to other SICPS tents or shelters. Modular by design, they are able to be connected end-to-end, side-to-side, or side-to-end. The tents are employed with operational facilities of IBCS EOCs to provide open ICE workspace, power distribution, lighting, environmental conditioning (heating and cooling), tables, lightweight/integrated flooring, and a common grounding system for the staffs. Figure 3-5 shows an ICE layout.

Figure 3‑4. ICE Layout ICE tents and support equipment are transported on a large tactical trailer derived from the standard TMSS (Trailer Mounting Support System) family of products. The trailer provides generator power, an Environmental Control Unit (ECU), and cargo space for support equipment. The ICE is issued at BTRY and BN echelons. The ICE at BN echelons supports the full range of AMD operational tasks. The EOC ICE provides for the collocation and integration of Functional and integrating cell activities. The Platoon echelon consists of one IBCS shelter with prime mover and generator. Addition of one ICE produces the BTRY echelon. The BN echelon is twice the BTRY echelon, consisting two shelters and two ICEs. All shelters and ICEs are common and interchangeable among echelons.

IFF System As shown in Figure 3-6, the IBCS stand-alone Identification Friend or Foe (IFF) capability is employed through the use of a receiver transceiver located on a rack inside of the EOC Shelter. A corresponding set of IFF system antennas consisting of a GPS and IFF unique antenna is located on the external surface of the EOC Shelter mounted on the roadside rear portion of the shelter.

Figure 3‑5. IBCS IFF System

IFCN

The IFCN consists of network components and transport media used for voice, data, and video information exchanges between IBCS components. From a network perspective, a component includes a radio interface to the IFCN connected to an intra-nodal LAN. IBCS uses the Harris Warfighter Information Network Tactical (WIN-T) Increment 2 interoperable Highband Network Radio (HNR), consisting of the Baseband Processing Unit (BPU) and Highband Network Waveform (HNW) RF Unit (HRFUe2-8Wch) antenna. Figure 3-7 shows the HRFUe2-8Wch antenna. The IFCN node hardware is common to and a part of each MEI (EOC, IFCN Relay) described in subsequent sections. Network communications components are integrated within the EOC Shelter with connections to the necessary external antenna components, while on the IFCN Relay they reside within the network with connections to the external antenna components mounted to the mast assembly.

Left: component photograph; Right: as integrated onto IFCN Relay mast Figure 3‑6. HRFU Antenna

The HRFUe2-8Wch antenna utilizes directive beam technology to achieve high-throughput mesh networking over long distances with enhanced spectrum efficiency. The antenna consists of 15 elements in the horizontal plane and one element at zenith. The technology takes advantage of the directive beams to determine links that do not interfere and allows multiple nodes to transmit and receive using the same time slot. This accomplishes a distributed architecture where radios track time division multiple access time slots and transmit on non-interfering links.

The IFCN nodes consist of common hardware across all configurations. All configurations utilize common hardware elements and interfaces across platforms that facilitate integration and maximum effective reuse. Figure 3-8 depicts the IFCN Network Node.

Figure 3‑7. IFCN Network Node Architecture

HNR components, including the network encryption elements, are used for all configurations. Hardware commonality and use of WIN-T and Commercial Off-the-Shelf (COTS) components in IFCN hardware ensure easy maintenance and spare parts provisioning.

V2 IFCN Relay During Engineering and Manufacturing Development (EMD), the IFCN Relay has evolved from the original version, called the Version One (V1) IFCN Relay to the Version Two (V2) IFCN Relay. The V2 IFCN Relay, shown in Figure 3-7, is the second version of this MEI. The main difference is the GFE M1061A1P2 trailer, palletized mast assembly, which was changed to allow greater flexibility, and increased load. It provides network components and transport media used for voice, data, and video information exchanges between IBCS components to allow a 150-km range. The Tactical Mast Trailer (TMT) is the Government-provided platform in which the hardware and software provide the V2 IFCN Relay (also known as P&F B-Kit) functionality to meet the IBCS performance requirement of a mobile IFCN communications node, with B-Kit functionality and interface, which extends connectivity to remote launchers and sensor platforms. The IFCN Relay can also function as a stand-alone IFCN communications relay to expand the range of Line-Of-Sight (LOS) communications over the horizons and around intervening terrain features.

Figure 3‑8. IFCN Relay v2

An IFCN Relay contains a HRFU, a PFPU and a fully integrated network enclosure. The network enclosure consists of the IFCN radio and its components, a time and frequency reference system, encryption devices, a classified Ethernet switch, and fiber media converters for A-side connectivity. All necessary external connections including A-Kit adapted sensors and weapons utilize media converters with TFOCA-II cable.

The IFCN Relay platform includes a 3kW generator. It includes an antenna mast housing the HRFUe2-8Wch antenna and HRFU connections for power, control, and RF that feed into the network enclosure.

Each Relay is connected to the receiving platform’s A-kit, Launcher Integration Network Kit (LINK), or other A-side connection. Details of the Relay interface with the Component Acquisition Programs (CAPs) may be found in MIS-DTL-56502, P&F B-Kit to A-Kit Interface Control Document (ICD).

ePFPU The ruggedized ePFPU consists of two Line Replaceable Units (LRUs) – the ePFPU and a Network Attached Storage (NAS). The ePFPU is a ruggedized enclosure containing six Single Board Computers (SBC), an Ethernet switch, two 800w power supplies, and supporting hardware (e.g., power distribution, structure). The ruggedized ePFPU operates at a nominal 28 VDC. The Processing Unit is a forced-air-over-conduction cooled 3U Open Voice Protocol Exchange (VPX) chassis. The forced air is pulled by the fan assembly through the air inlets along the front of the unit, and expelled out the rear. A 3U Open VPX form factor has been selected for its compact size and heat dissipation qualities.

Processors are loosely coupled via ten-gigabit backplane Ethernet connections. Ethernet also supports all connections external to the ePFPU. Within the red domain, a multi-layer Ethernet switch manages switching. These switches have transient voltage suppressors on each port to protect from Electrostatic Discharge (ESD), cable discharge, and lightning and other induced voltage surges. They have built-in test capability, security features, and Internet Protocol (IPv6) capability, while supporting speeds up to ten gigabit (GB) per second. The ePFPU provides computing capabilities suitable for rugged, all-weather environments.

The NAS is a rugged enclosure housing solid-state drives and control electronics. The NAS is the storage/hard drive for the ePFPU. The NAS has a removable storage bay at the top of the device that can be used for data harvesting and data transfer. The ePFPU chassis provides accommodations for mounting the NAS directly to it, either on the top or the side.

RBD Development and MTBF Prediction Per the Boeing ePFPU B_A241 RAM Prediction Report and shown in Figure 4-1, the LRU consists of one EMI assembly, two power supplies, one XMC, six SBCs, one fan assembly, one fan power cable, one front panel assembly, one card cage assembly, one NAS assembly, one NAS power cable, one 3U switch, and one backplane assembly. The power supplies are actively redundant as each is possible of handling the power demands of the unit on its own and thus modeled in a parallel configuration. The remaining components are in serial, as they do not have redundancy at the SRU level. The ePFPU RBD for MTBF is shown in Figure 3-9.

Figure 3‑9. ePFPU Reliability Block Diagram for MTBF RBD Development and MTBFc Prediction Per the Boeing ePFPU B_A241 RAM Prediction Report Section 4.1.2 Mission Criticality was based on the IBCS definition of mission critical which states that any failures that will impact the systems’ ability to perform engagement operations will be considered critical. However, failures that would present startup, or would be detectable at startup, are not considered mission critical, as these failures would be detected prior to starting a mission and a new unit would be swapped out. Thus, any failures that affected system health monitoring operations, but not engagement, were correctable by redundancy, and/or had no effect on engagement, were considered non-mission critical failures. These failures were confirmed to be non-mission critical via the ePFPU FMECA and Testability Report (PF1-13105 Rev. B) and were not included in the MTBFc prediction. These non-mission critical failure modes in the FMEXA can be identified by having only failure modes with mission criticality categories of only III and IV.

The ePFPU MTBFc should represent the bare minimum of components required for the ePFPUto fulfill its mission. Thus, one of the PSUs was removed from the prediction due to their redundancy. The representative failure rate of the PSU that was used for this calculation was the average of the two PSUs. The dormant SBC was also not considered in this calculation, as the SBC is dormant and thus not considered critical to engagement. The EMI assembly, card cage assembly, backplane assembly, and front panel assemblies had components that were non-mission critical that were removed from the block failure rate calculations as well. The ePFPU Reliability Block Diagram for MTBFc is shown in Figure 3-10.

Figure 3‑10. ePFPU Reliability Block Diagram for MTBFc ePFPU Reliability Results Per the Boeing ePFPU B_A241 RAM Prediction Report Section 5.0 Reliability Results Table 3-1 below summarizes the calculated ePFPU MTBF and MTBFc predictions according to the RBDs shown previously in Figure 4-1 and Figure 4-2.

Table 3‑1. ePFPU MTBF, MTBFc, vs. Requirement

Improved Architecture: New S280 EOC and V2 IFCN Configuration In this section, we reflect on the changes incorporated from the old CPP Based EOC to the S280 Based EOC and the V1 IFCN to the V2 IFCN shown in Table 3-1. The updates are indicated in yellow. Gray shows no change. The following tables were updated October 2018.

Table 3‑2. EOC “Shelter”: CPP Configuration vs S280 Configuration

*New module added, see drawing ALH-210931 Rev 03

9800-13900-0000 9800-07060-9030 Disk Drive Unit &

FBCB2 CPU

FBCB2 CPU

Changes incorporated from the old CPP Based ICE to the S280 Based ICE are indicated in yellow shown in Table 3-2. Gray shows no change (October 2018). The ICE has undergone a complete redesign.

Table 3‑3. EOC - “ICE”: CPP Configuration vs S280 Configuration

Changes incorporated from the V1 IFCN Relay Configuration to the V2 IFCN Relay Configuration are indicated in yellow, while gray reflects no change (October 2018) shown in Table 3-3..

Table 3‑4. IFCN Relay: V1 vs V2 Configuration

Requirements Compliance The IBCS EOC and IFCN Mean Time Between Critical Failures (MTBFc) requirement, prediction and compliance is shown in Table 3-5.

IBCS System Spec Parent Requirement 1096 states “a single EOC shall have a Mean Time Between Critical Failure (MTBFc) of not less than 893 hours. The MTBFc includes all Contractor Furnished Equipment and Government Furnished Equipment.”

The EOC (Hardware, Software, and Cabling) MTBFc prediction of 955.41 Hours is based on a Mission Pulse Duration of 72 hours, an EOC (includes “k of n” ICE configurations) Hardware of Probability of Success or Reliability of 0.9274, an MTBFc of 955.6714 Hours, an assumption that the EOC Cabling Probability of Success or Reliability is 1.0 and an MTBFc of 7,199,964 Hours, and an assumption that the Software Probability of Success is Reliability of 1.0 and a MTBFc of 7,199,964 Hours.

The Relay (Hardware, Software, and Cabling) MTBFc prediction of 1198.7689 Hours is based on a Mission Pulse Duration of 72 hours, a Relay Hardware of Probability of Success or Reliability of 0.9417, an MTBFc of 1199.1682 Hours, an assumption that the Relay Cabling Probability of Success or Reliability of 1.0 and a MTBFc of 7,199,964 Hours, and an assumption that the Relay Software Probability of Success or Reliability of 1.0 and a MTBFc of 7,199,964 Hours.

The EOC and Relay MTBFc prediction versus the EOC and Relay MTBFc requirement is shown in Table 3-6. The EOC MTBFc Prediction show a margin of 62.4178 Hours and the Relay MTBFc Prediction shows a deficit of 536.2311 Hours respectively. Thus, the EOC MTBFc is in compliance and IFCN Relay MTBFc Predictions is not in compliance with their respective IBCS EOC and IFCN MTBFc requirements.

Table 3‑5. IBCS EOC and IFCN RAM Requirements Compliance

CP3845

Hours (Hardware, Software, Cabling, & “k of n” ICE Workstations and Transit Cases Configuration) Yes Section 5.0

PF965

Hours (Hardware, Software,& Cabling) No Section 5.0

EOC and Relay MTBFc Prediction vs. Requirement and Margin results are shown in Table 3-6.

Table 3‑6. EOC and Relay MTBFc Prediction Margin

Prediction Margin

0. Functional Block Diagram A functional block diagram illustrates the operation and interrelationships between functional entities of a system as defined in engineering data and schematics. A functional block diagram will provide a functional flow sequence for the system and each indenture level of analysis and present hardware indenture used for both hardware and functional method FMEA’s. MIL-M-24100 procedures and techniques for developing major functional diagrams may be used for guidance in developing functional block diagrams.

At the present time, the functional diagrams are being developed to depict the functional flow sequence for the system and each indenture level of analysis and present hardware indenture used for both hardware and functional method.

RAM Modeling It should be noted that software configurations are not addressed in this RAM report deliverable. A more technical and realistic approach to presenting the IBCS Software Configurations and Software Reliability Prediction analysis will be reported in the next deliverable of the A241 RAM Prediction Report.

However, for the current deliverable of the CDRL A241 RAM Predictions and Analysis we are making the following assumptions regarding the IBCS System Model with respect to Software and Cabling:

1. IBCS Software will be treated as one entity with a Probability of Success or Reliability of 1.0 See Section 4.7 for the Software Reliability Prediction basis.

2. IBCS EOC and Relay Cabling will be treated as one entity with a Probability of Success or Reliability of 1.0 (See Appendix D for the IBCS Cable List) This section of the report lists the ground rules and assumptions used for RAM modeling, and describes the mission phases, operational modes and environmental profiles. It also explains the data source hierarchy used for RAM modeling and explains the block diagrams employed.

The Reliability Block Diagrams (RBDs) and mathematical models are not only used to assess the reliability metrics of IBCS and its sub-systems but are also used to improve these metrics for the systems. For example, many of the parts selections involve studies comparing various options. The selection process for these studies considers reliability parameters as one of the criteria. Another way that the reliability modeling is used to improve system reliability is through design redundancy. The reliability modeling can be used to determine an appropriate reliability metric for the current design and then assess the metric for alternative designs. This type of analysis provides important information for designers to use in choosing a final design.

Model Analysis, Ground Rules and Assumptions The ground rules for IBCS (S-280) RAM modeling are as follows:

1. A failure is defined as an event, or inoperable state, in which any item or part of an item does not, or would not, perform as previously specified.

2. An IBCS mission critical function is an IBCS function whose failure results in the loss of the ability to perform Engagement Operations or a severe degradation in that ability.

3. A mission critical failure is any failure of hardware or software resulting in a failure mode that prevents a mission critical function from being performed or that severely degrades the performance of that function. For Mean Time between Critical Failures (MTBFc) calculations, mission critical failures are those failures identified in the IBCS-A243 Failure Modes, Effects and Criticality Analysis (FMECA) Results as having a reliability severity classification of Category I, II, III-1R, or III-2R per Table 4-1.

4. For Reliability Engineering, a mission critical part is any hardware or software that has a critical failure mode.

5. MTBFc is defined to be the mean number of life units during which all critical parts of the item perform within their specified limits, during a particular measurement interval under stated conditions. This definition is from MIL-STD-721, adapted from Mean Time between Failures.

6. MTBFc is calculated as the integral of the reliability (as a function of time) with respect to time, integrated from time zero to time approaching infinity.

7. Mean Time to Repair (MTTR) is defined as the sum of corrective maintenance times at any specific level of repair, divided by the total number of failures within an item repaired at that level, during a particular interval under stated conditions. This definition is from MIL-STD-721.

8. All predictions are for a mature system.

9. Failure rate data from field experience in similar conditions is to be used when available. If field data in similar conditions are unavailable, test data, vendor data, MIL-HDBK-217F, or similar-to analysis may be used.

10. Predictions assume constant failure rates at the lowest part level unless explicitly stated otherwise.

11. It is currently assumed that all hardware operates with a one hundred percent duty cycle during emplacement.

12. All hardware is maintained per the IBCS-recommended maintenance procedures and by properly trained maintenance personnel. See CDRL A285, Integrated Support Plan (IPS), for details.

13. All consumables are present in sufficient quantities unless otherwise stated.

14. All inputs (including software commands and power) to the item being analyzed are present at nominal values unless otherwise stated.

15. The expected time difference from the first evidence of a fault to the occurrence of the actual failure is considered on a case-by-case basis. This information is applicable to prognostics.

16. Probabilities associated with human errors are not explicitly included unless the design requires a human to perform beyond what is judged reasonable limits.

17. Environments, operational modes, and mission profiles are per the Operational Modes Summary / Mission Profile (OMS/MP) and relevant specifications.

18. Reliability predictions for the EOC and Relay operational environment are based on a Ground Mobile (GM) environment.

Table 4‑1. Reliability Severity Classification Criteria

Definition Severity Description

Mission Phases and Operational Modes Mission phases and operational modes play an important part in the functionality of IBCS. The RAM models, allocations, and predictions use the Operational Modes Summary / Mission Profile (OMS/MP) to define these phases and modes. Analysis considers operations, moving, and maintenance phases. Per the OMS/MP, each 180-day period (4,320 hours) has 4,098 hours of combined operations and maintenance. Mobile operations consists of 222 hours. In addition, 150 hours of maintenance is shown in Table 4-2. The system operations and maintenance (150 hours) can be performed concurrently. During operations, a subsystem may be supporting engagement operation or future planning or both. Much of IBCS is not required to operate during moving, although some of the systems are. Table 4-2 below reviews the OMS/MP.

Table 4‑2.