# Presentation: 669864

## Measured by cumulative maintenance task hours ‘clock hours’
Note:Some direct flt hardware processing for Orbiter landing & SRB recovery unavailable at same level of analytical detail  

- Measured by cumulative maintenance task hours ‘clock hours’
- Note:Some direct flt hardware processing for Orbiter landing & SRB recovery unavailable at same level of analytical detail

**GENERIC**
**OPERATIONS**

**DESIGN DISCIPLINES**

**Top Level Results of STS-81****Direct Work Content Analysis (1 of 6)**

## Sorts largest contributing cells in previous chart (by ops function & design discipline)

**Top Level Results of STS-81****Direct Work Content Analysis (2 of 6)**

## Top Level Results of STS-81Direct Work Content Analysis (3 of 6)

**Top Level Results of STS-81****Direct Work Content Analysis (3 of 6)**

## Top Level Results of STS-81Direct Work Content Analysis (4 of 6)

**Top Level Results of STS-81****Direct Work Content Analysis (4 of 6)**

## Top Level Results of STS-81Direct Work Content Analysis (5 of 6)

**COMMON**
**OPERATIONS FUNCTIONS**

**Generic Top-Level Operations**

**Top Level Results of STS-81****Direct Work Content Analysis (5 of 6)**

## Top Level Results of STS-81Direct Work Content Analysis (6 of 6)

**Top Level Results of STS-81****Direct Work Content Analysis (6 of 6)**

## Review of Root Cause Results

**Start with Common Operations Functions :**
**Excessive Unplanned Troubleshooting and Repair (~24%)**
- _Preliminary Analysis of Design Root Causes:_
- Flight & ground system dependability (i.e., design life and element reliability in relation to total parts count)
- Flight & ground system complexity manifested through high part counts in components, subsystems and redundancy management techniques
- Need to balance maintainability while achieving safety objectives (implement NSTS 5300.4/1D-2, Chapter 4 Maintainability Assurance items; i.e., effectively implement design corrective action and continuous improvement program)
**Complex Assembly, Handling, Access, & Mating (~19%)**
- _Preliminary Analysis of Design Root Causes:_
- Number of launch site-installed subsystems and components per element
- Number and complexity of interfaces across assembled flight elements
- Number and frequency of reusable flight element modules and components requiring disassembly/re-assembly (SSME’s OMS/RCS pods, RMS,etc.)
- Number of single use, limited life components, requiring assembly and access
- Decomposition of design discipline functions creates a non-integrated design process that duplicates and proliferates hardware without regard to recurring operations and infrastructure

## (Continued)
Excessive Requirements for Systems Servicing (18%)
Preliminary Analysis of Design Root Causes:
Number and type of different fluid commodities requiring routine servicing and separate flight/ground interfaces
Number of limited life items (relates to design life root cause)
Decomposition of design discipline functions creates a non-integrated design process that duplicates and proliferates hardware without regard to recurring operations and infrastructure

Resulting Functional Verification (~14%)
Preliminary Analysis of Design Root Causes:
Lack of demonstrated operational reliability (i.e., routine system operation without need for functional restoration between flights)
Over-redundancy in design to overcome lack of demonstrated reliability
Number of critical flight functions requiring functional verification
Amount of reusable flight element disassembly and re-assembly, and amount of expendable flight item assembly resulting in the requirement for recertification prior to each flight commitment 
Amount of automation employed in the system (flight and ground elements)

**Excessive Requirements for Systems Servicing (18%)**
- _Preliminary Analysis of Design Root Causes:_
- Number and type of different fluid commodities requiring routine servicing and separate flight/ground interfaces
- Number of limited life items (relates to design life root cause)
- Decomposition of design discipline functions creates a non-integrated design process that duplicates and proliferates hardware without regard to recurring operations and infrastructure
**Resulting Functional Verification (~14%)**
- _Preliminary Analysis of Design Root Causes:_
- Lack of demonstrated operational reliability (i.e., routine system operation without need for functional restoration between flights)
- Over-redundancy in design to overcome lack of demonstrated reliability
- Number of critical flight functions requiring functional verification
- Amount of reusable flight element disassembly and re-assembly, and amount of expendable flight item assembly resulting in the requirement for recertification prior to each flight commitment
- Amount of automation employed in the system (flight and ground elements)

**Review of Root Cause Results**

## (Continued)
Excessive Facility & Equipment Refurbishment/Preps (~12%)
Preliminary Analysis of Design Root Causes:
Ground system dependability (i.e., design life and hardware reliability in relation to total parts count)
Lack of ground launch system design life to withstand the induced launch environment for frequent, routine launches
Number of separate Ground Support Equipment items to support routine operations driven by flight systems design complexity 
Need to balance maintainability while achieving safety objectives (implement NSTS 5300.4/1D-2, Chapter 4 Maintainability Assurance items; i.e., effectively implement design corrective action and continuous improvement program)

Complex/Customized Payload Integration with Flight Element     (5%--However, critical path impact is considered to be significant)
Preliminary Analysis of Design Root Causes:
Unique vehicle payload accommodations customized for each flight during routine on-line operations--by design.
Large number of flight-unique vehicle-provided services to the payload driving on-line operations ( lack of payload cg and weight margin)

**Excessive Facility & Equipment Refurbishment/Preps (~12%)**
- _Preliminary Analysis of Design Root Causes:_
- Ground system dependability (i.e., design life and hardware reliability in relation to total parts count)
- Lack of ground launch system design life to withstand the induced launch environment for frequent, routine launches
- Number of separate Ground Support Equipment items to support routine operations driven by flight systems design complexity
- Need to balance maintainability while achieving safety objectives (implement NSTS 5300.4/1D-2, Chapter 4 Maintainability Assurance items; i.e., effectively implement design corrective action and continuous improvement program)
**Complex/Customized Payload Integration with Flight Element     (5%--However, critical path impact is considered to be significant)**
- _Preliminary Analysis of Design Root Causes:_
- Unique vehicle payload accommodations customized for each flight during routine on-line operations--by design.
- Large number of flight-unique vehicle-provided services to the payload driving on-line operations ( lack of payload cg and weight margin)

**Review of Root Cause Results**