FA8773-10-R-0088_QandA.pdf

Draft RFP FA8773-10-R-0088

Cyberspace Infrastructure Planning System (CIPS)

Vendor Comment/Questions and Government Responses

1. The Government has requested comments and feedback regarding the use of CMMI (Capability

Maturity Model Integration) as an evaluation standard for this effort. We respectfully submit the following comments in that regard.

DISSCUSION: We do not feel that it is in the Government’s best interest to use CMMI as an absolute

“go/no-go” qualifier for this contract. We understand that the final RFP will be released as an 8(a) set-aside. Using the CMMI Level 3, or any level, rating in combination with the 8(a) set-aside provision will severely limit the number of potential respondents to the RFP, unfairly excluding a large number of fully qualified vendors from participation in the competition.

The reality is that it is expensive to obtain an official CMMI rating; an expense that potentially suitable companies may not have elected to bear. However, these very same companies may be completely compliant at the requisite CMMI Level in one or more projects; that is, they have opted into the process but have not committed to the expenditure to obtain a rating because they view its return on investment as out of proportion to the financial cost of obtaining the formal rating.

Unlike an ISO certification, such as ISO 9001:2008, the issuance of a CMMI rating is not governed by an authoritative body such as the International Organization for Standardization (ISO). In acquiring an ISO certification, while a failure to fully meet part of a standard may not be a disqualifying point, there are procedures in place to ensure that those deficiencies are corrected in a timely fashion. There are no such procedures in place for a CMMI rating; i.e., a deficiency may be noted but there is no process in place to encourage rapid response via a deficiency correction action. Thus a deficient process could remain in place throughout the three year tenure of a single CMMI rating period.

The mere fact that an organization holds a CMMI rating does not assure the Government that the division of the organization that will perform the tasks of the contract is in any way associated with the division holding the rating. It is possible, and probably quite common, for a single division or branch of an organization to receive a CMMI rating, while the rest of that organization is completely free of any requirement to participate or adhere to the procedures of that division or branch. In fact, it could be possible for a Prime to hold the requisite CMMI rating, but be teamed with a company without any

CMMI rating and deliver up to 49% of the work to be performed into the hands of technicians totally unfamiliar with the concepts of a continually improving process.

We also note that the Performance Work Statement (PWS), paragraph 1.4.1.2, Policy Compliance, requires the contractor to “adhere to Department of Defense, Air Force, Major Command, Installation, Organizational, or any other Government mandated guidance and directives while developing and maintaining CIPS.” This would imply that procedures and policies to be used during the development and maintenance of CIPS are either in place, or would be directed to be developed, and that these would be based in large part on “best practices” and therefore would already provide a foundation for management of the project in a fashion that is CMMI compliant. This assumption is strengthened through other requirements of the PWS such as paragraphs1.4.2.1.6, 1.4.2.7,1, 1.4.3 and its subparagraphs, 1.5.1.6, 3.5.3.1, 3.5.3.2 and 3.7.5.

We feel that the Government would be better served in this instance by relying more upon Past

Performance and Experience and the feedback provided by informed representatives of the client organization by way of surveys, or formal performance feedback venues such as Contractor Performance

Assessment Reports (CPAR) and the Past Performance Information Retrieval System (PPIRS). This would provide a much deeper pool of qualified competitors to evaluate and award from, which in turn

Vendor Comment/Questions and Government Responses provides the Government with more opportunities to engage the services of a world-class contractor to perform the contract.

RECOMMENDATION: In the event that it is the Government’s position that CMMI is crucial in the source selection process, then we would recommend that a specific lower level be declared as acceptable or that any level is acceptable as a minimum.

GOVERNMENT RESPONSE: The Government agrees that use of CMMI Level 3, while advantageous, would be more restrictive for selection criteria. Thus, the Government will be revising the Sections L & M of the solicitation to reflect a minimum of CMMI Level 2 assessment as a technical evaluation criterion.

2: The Government has requested comments and feedback regarding the page limitations specified in

Sections L and M of the DRFP. We respectfully submit the following comments in that regard.

Additionally, we are commenting on the Recency Assessment, paragraph 2.2.1 of the DRFP.

DISCUSSION: No page limit has been established for the Present/Past Performance Information (PPI) write-ups. We would suggest the length of these write-ups be specified as open-ended or that a reasonable limit be established for them.

The Government’s desire that a PPI that applies to the Prime and any proposed subcontractor be contained within a single PPI reference (DRFP paragraph D.5) makes suggesting a maximum length for these exhibits difficult. In our experience, separate references for the Prime and any subcontractor(s) proposed with a page limit per reference have facilitated good competition.

RECOMMENDATION: Given the amount and type of information requested, we would suggest a 5 page limit to the information provided to address paragraph 6, subparagraphs g, h, i, j, k and l of the DRFP.

This would translate to a 6 to 7 page total limit per PPI exhibit, assuming that this section is subject to the provisions of Paragraph B.2.a of the Proposal Instructions rather than the provisions of paragraph B.2.b.

GOVERNMENT RESPONSE: A page limitation will be assigned for submission of PPI on the finalized RFP.

3: In addition, we respectfully submit the following comments regarding paragraph 2.2.2, Relevancy

Assessment, of the DRFP.

DISCUSSION: Within Focus Area 1, System Administration and Development, it is stated that the contract reference is NOT RELEVANT if it was not Oracle based even though it may meet all other criteria. This determination would seem to be overly restrictive. Similar systems are already in use by the U.S. Air Force that are not Oracle based, and experience with those systems would seem at least

SOMEWHAT RELEVANT to the effort under consideration.

In point of fact, we shouldn’t even be considering these differences at this level. It would seem, for the purposes of contract award, that successful experience in managing a contract that required the support of an enterprise scaled database, with the other prerequisites of GIS use, accessibility, user authentication and user base size being met, would be sufficient. At the contractor level, this requirement boils down to a question of whether or not the contractor has been able to identify, attract, hire and retain qualified technicians in a very specialized area of expertise.

Vendor Comment/Questions and Government Responses

RECOMMENDATION: Replace “Oracle-based” with “Enterprise Database Management Application.”

If a company is able to do it in support of a Microsoft SQL based enterprise effort that did have GIS incorporation, or other Oracle efforts that perhaps did not involve GIS, then the Government should have reasonable assurance that they can provide that same level of support for this contract.

GOVERNMENT RESPONSE: The requirement stands as written. CIPS is a mature, Oracle-based system requiring experienced Oracle professionals to maintain it.

4: Finally, we do not find that there are sufficient requirements definitions to provide the government with a meaningful proposal.

DISCUSSION: There is no guidance as to the level of effort required to successfully perform the contract.

We see two items with respect to level of effort. The first one deals with the anticipated level of effort in each focus area. There is currently no guidance as to the number and types of labor categories involved, or to the size and complexity of the development effort or even to the number of anticipated help desk calls. The second item is guidance as to the number and types of labor categories involved to include labor category duties, responsibilities, experience and education requirements; size and complexity of the development effort, size and complexity of the database administration effort, and anticipated help desk workload, including number and types of calls and number and type of requests of “walk-ins” mentioned in paragraph 1.4.5.2 of the PWS. A true performance based contract gives the prospective bidder enough information to propose the most efficient staffing structure associated with solid industry standard processes.

RECOMMENDATION: Provide enough additional detail regarding the workload so a prospective bidder can perform a proper manpower analysis.

GOVERNMENT RESPONSE: See final PWS to be posted with RFP. In a typical week the

HD receives 31 calls, 15 e-mails and 2 walk-ins. Cumulative totals since November 2006, there have been a total of 7,226 HD contacts (excluding walk-ins).

5. Is this a new effort?

GOVERNMENT RESPONSE: No

6. If this is not a new effort, who is the incumbent Prime Contractor and what is the contract number?

GOVERNMENT RESPONSE: L-3 Services, Inc is the contractor and the contract number is FA8773-09-F-0048.

7. Are the project manager (PM) and alternate project manager (APM) full-time direct bills to the contract?

GOVERNMENT RESPONSE: The PM is billed at 1/3 of the person and there is no APM.

8. Will the PM and APM be given on-site office space?

GOVERNMENT RESPONSE: Yes

9. What are the current labor categories and staffing numbers?

Vendor Comment/Questions and Government Responses

GOVERNMENT RESPONSE: Please utilize the information in the RFP package to formulate a proposal.

10. What is the “existing ad hoc creation and reporting tool” referenced in paragraph 1.4.3.7 of the PWS?

GOVERNMENT RESPONSE: LOGI XML Adhoc. Reference Appendix 5 of the PWS.

11. What is the “approved software lifecycle management tool” as mentioned in paragraphs 1.4.3.8, 1.4.5.4, and 1.4.5.5 of the PWS?

GOVERNMENT RESPONSE: Defects are initially captured via an integrated CIPS application. Once evaluated, valid bugs and enhancements are entered into Microsoft Team

Foundation Server (TFS). The Government also uses Microsoft Test Manager 2010.

12. Paragraph 1.4.4.6 of the PWS states “The preferred training location will be either a contractor provided training facility or a training facility at the 38 th CEG.” Paragraph 1.3.2 of the PWS states that

“Work will be accomplished on-site at Tinker AFB, OK.” Please clarify.

GOVERNMENT RESPONSE: Training will be conducted at Government facilities. The

PWS will be changed to reflect this. Average class size is 20 students. Contractor will be required to provide training materials and instructor.

13. Paragraph 1.4.4.6 of the PWS states “The preferred training location will be either a contractor th CEG.” Is there an established training facility at the 38 th CEG at this time?

14. Paragraph 1.4.4.6 of the PWS states “The preferred training location will be either a contractor th CEG.” If the contractor is to provide the training facility, what is the anticipated maximum class size and what training aids/tools would be required at the facility?

GOVERNMENT RESPONSE: Reference response to question 12.

15. Paragraph 1.4.4.6 of the PWS states “The preferred training location will be either a contractor th CEG.” Would furnishing of a contractor provided training facility with required furniture, ADPE, internet connectivity, etc. be with Government

Furnished Property? If not, would the cost of the facility and training-related furnishings/equipment/support be reimbursable expenses?

GOVERNMENT RESPONSE: Not applicable. Reference response to question 12.

16. Please clarify the definition of “normal duty hours”. Paragraph 1.3 of the PWS states that normal duty hours are from 0800 to 1700, however it does not specify if this includes weekends and does not address Federal Holidays. A finer definition is required in order to verify and validate the Performance

Objectives and Performance Thresholds in Section 2 of the PWS. For example, Section 2 states that one

Vendor Comment/Questions and Government Responses

Performance Objective is to “Maintain CIPSNET and CIPSNET servers in order to provide a minimum availability of 96% during Tinker AFB normal duty hours.” The associated Performance Threshold is

“No more than eight (80) cumulative hours down-time during normal duty hours at Tinker AFB within a contract year.” Calculation of “normal duty hours” does not correlate with the 80 cumulative hours:

Using calendar year 2011 as a sample contract year reveals that there are 2250 “normal duty hours” in that time frame: 365 days minus 53 Saturdays, 52 Sundays and 10 Federal holidays = 250 duty days * 9 hours per duty day = 2250 hours. 96% availability of 2250 hours would provide for 90 hours cumulative down time, not 80 hours.

GOVERNMENT RESPONSE: 80 cumulative hours is the requirement. Reference the

PWS in the final RFP.

17. Paragraph 1.4.5.1 of the PWS states that Contractor Help desk personnel shall be “available during normal duty hours at a Government-provided Help Desk location … on Tinker AFB,OK”. Paragraph

1.5.3.1 of the PWS states that the contractor will “provide a full time CIPS Help Desk available 24 hours a day, 7 days a week. Help Desk personnel shall perform their duties at a Government provided Help

Desk location on Tinker AFB, OK…” Please clarify if the CIPS Help Desk is to be a “during normal duty hours” or a 24x7x365 operation.

GOVERNMENT RESPONSE: The requirement referenced in 1.5.3.1 is an optional item.

24/7 Help Desk services will only be required if the Government chooses to fund and exercise this option. Otherwise, the Help Desk services are only to be provided during Tinker AFB normal duty hours as defined in 3.1.1 of the PWS.

18. CMMI Maturity level 3 does not guarantee that the organization understands the requirements or has the ability to develop a sound solution to the requirements in the PWS and therefore should be given appropriate weight along with the offeror’s technical solution. A level 2 company that has a solid grasp of the requirements as shown by their solution may be the best fit for this task.

Since this appears to be primarily a sustainment task order with some modernization, having a CMMI level 3 requirement may be unnecessary and will limit competition. We recommend the following factors be considered:

Whether the system was developed with CMMI-Dev 3 processes

Whether the current prime is CMMI-Dev 3 for this project? If not, would being CMMI-Dev 3 make the incumbent a better performer and thereby increase the ability of CIPS to support the warfighter?

Whether the system complexity requires it (LOC, # components, COTS vs. developed SW, etc)

Whether the government already have adequate processes in place that may be adopted or adapted by the offeror

Whether the cost for CMMI Level 3 suppliers will be more than CMMI 2 and does that cost outweigh the benefits

GOVERNMENT RESPONSE: Reference response to question 1.

19. “Contractor” would like to note that the impending Air Force’s NETCENTS II Network Operations contract only required CMMI Level 2 - and that contract includes major software and infrastructure

(including CITS) development and integration Air Force wide.

Vendor Comment/Questions and Government Responses

20. It is not clear to us whether or not this RFP asks for a technical approach since the only subfactors in

Section M refer to CMMI ratings and Staffing Approach. If the final RFP includes the specific requirement for a technical approach we do not feel that 25 pages would be sufficient to provide a technical approach that suitably demonstrates the offeror’s capability to meet the requirements and provide a staffing approach as well.

GOVERNMENT RESPONSE: The Final RFP will address the two same subfactors;

therefore, the page limitation will remain at 25 pages.

21. “Contractor” is not clear why this code is required for this contract as it appears that this task is to provide Professional, Scientific, and Technical Services for the CIPS software and hardware environments. According to the NAICS definitions, code 517110. This Code appears to lack justification based on the DRFP task descriptions. Coupling the NAICS Code 517110 and the CMMI Level 3 requirements will severely limit competition.

GOVERNMENT RESPONSE: NAICS Code 517110 was erroneously referenced in Section

L. The correct NAICS is 541512.

22. “Contractor” recommends including specific mention of supporting environments (such as development and test) required for CIPS development, integration, and testing.

Is there any performance testing being done?

What tools are being used today to measure availability?

There is similar work being done in many environments outside the Air Force. “Contractor” recommends specifying that any relevant past performance will be considered.

GOVERNMENT RESPONSE: Performance testing is currently not being performed. No tools are being used to measure availability. Relevancy has been defined in Section M of the solicitation.

Government –only experience was not listed as a factor for determining relevancy.

23. “Contractor” suggests that a Full & Open competition will meet government requirements and provide the advantage of greater competition.

GOVERNMENT RESPONSE: IAW FAR 19.805(a)(1), an acquisition offered under an 8(a) program shall be awarded if there is a reasonable expectation that at least two eligible and responsible 8(a) firms will submit offers and that award can be made at fair market price. Our market research results identified two eligible 8(a) participants.

24. Based on the requirements specified in the draft RFP, it appears that CMMI Level 3 is more than beneficial to the Government. CMMI Level 2 specifies that “the organization has ensured that requirements are managed and that processes are planned, performed, measured, and controlled”; also, “commitments are established among relevant stakeholders and are revised as needed; work products are reviewed with stakeholders and are controlled.” This description seems more appropriate for CIPS, and requiring a higher level could be increasing cost and reducing competition unnecessarily.

Recommendation: Given that CIPS is an existing system, we recommend the AF reduce the required

CMMI level to Level 2.

Vendor Comment/Questions and Government Responses

25. In Section M, 2.1 Factor 1, Subfactor 1 - Is the government looking for CMMI level 3 certified primes or will a CMMI Level III team member suffice to meet requirements?

GOVERNMENT RESPONSE: Regarding CMMI level, reference response to question 1.

In addition, Prime must meet the CMMI requirement.

26. Will the AF evaluate the CMMI level of the overall team, to include subcontractors, rather than merely the prime?

Recommendation: We recommend considering the CMMI capabilities of overall team, allowing maturity level of the subcontractors equal to that of the primes.

GOVERNMENT RESPONSE: Reference response to question 25

27. In Section M, 2.1 Factor 1, Subfactor 2 c. - Is the existing staff in compliance with 8570 and meeting all certification and experience requirements for this procurement? If not, how much time will the government allow to bring them up to compliance and who will fund the training effort?

GOVERNMENT RESPONSE: The certifications held by the incumbent staff are irrelevant to this acquisition. Reference PWS of final RFP for time frame to acquire required certifications.

The Government will not pay for these certifications.

28. Will the past performance of the subcontractors carry as much weight as that of the prime?

Recommendation: We recommend weighting the past performance of the subcontractors equal to that of the primes.

GOVERNMENT RESPONSE: Yes, see RFP Section M, paragraph 2.2.4.

29. Can the Government please give clarification on what the page limit is for Past Performance?

GOVERNMENT RESPONSE: See response to Question 2.

30. Would the government consider providing more workload details or a headcount of incumbents currently performing the tasks included in the PWS?

GOVERNMENT RESPONSE: See response to Question 9.

31. In section 1.4.2.7.1 of the PWS, there is mention of quarterly verification of back-up recoverability.

Will these DR exercises be performed on- or off-site? If off-site (i.e. at a recovery site), will travel be covered by the government as in 3.7.11?

GOVERNMENT RESPONSE: Quarterly verification is conducted on-site at Tinker AFB.

The Contractor is not responsible for the verification, but simply assists the Government in the verification process.

Vendor Comment/Questions and Government Responses

32. In regards to section 1.4.2.7.1, will contractors be expected to participate in DR readiness exercises including unannounced DR drills?

GOVERNMENT RESPONSE: The Government does not currently conduct unannounced

DR drills, nor does the Government conduct DR readiness exercises. We simply ensure that CIPS can be fully restored IAW the CIPS Disaster Recovery Plan (DRP).

33. Will we be allowed to submit an OCI mitigation plan to allow the winning prime and/or their subcontractors the opportunity to work future CITS requirements? Since CIPS is a software system, it would be easy to separate infrastructure personnel/organizations CIPS providers.

Recommendation: We recommend accepting OCI mitigation plans and allowing primes or subcontractors to perform CITS infrastructure requirements as long as proper fire walls are in place.

34. Will projects listed in PWS section 1.4.4 impact the contractor’s ability to compete in future related opportunities due to OCI?

GOVERNMENT RESPONSE: Requirements listed in section 1.4.4 do not apply to future related opportunities.

35. In PWS section 1.4.4.6, there is mention of users training. Is there an expectation that the contractor will provide a training facility equipped with relevant hardware and connectivity? There is mention of a maximum of once a month classes. How many students per classes? What are the specifications for the classroom requirements (equipment, facility clearance…)?

GOVERNMENT RESPONSE: Reference response to question 12

36. In PWS section 1.4.5.7 there is mention of help desk metrics but the services summary had only one service level indicator and it is that the help desk be manned. Would the government provide a list of service level metrics for the help desk?

GOVERNMENT RESPONSE: Refer to PWS of final RFP.

37. Please specify anticipated travel requirements. Travel should be separate from the sustainment CLIN so we don’t erroneously increase the anticipated cost of sustainment.

Recommendation: Recommend AF separate travel into a separate cost reimbursable CLIN and AF provide their estimate for all bids.

GOVERNMENT RESPONSE: The travel CLIN is separate as CLIN 0005; see Schedule B.

38. Can the Government please clarify where in the Technical Volume offerors should respond to the

PWS requirements?

Vendor Comment/Questions and Government Responses

GOVERNMENT RESPONSE: Prepare the Technical Volume addressing only the content in the RFP Section L-1, paragraph C, Part I.

39. Are help desk incidents/calls/walk-ins captured and their lifecycle managed in an application? Is it

Remedy? If not, what is the application in use?

GOVERNMENT RESPONSE: The CIPS PMO does not use Remedy. Reference response to question 11.

40. How does CIPS interface with all CITS stakeholders (e.g. the CITS PMO at Hanscom AFB).

Recommendation: Provide CIPS CONOPS to industry prior to final RFP so all can accurately understand how CIPS interfaces with all CITS stakeholders.

GOVERNMENT RESPONSE: Any user wishing to access CIPS data must have a CIPS account. However, the use of CIPS by the various SPOs is an irrelevant issue for contract award.

41. Will the AF provide the following for the current CIPS performance: Workload projections; Current

Organization Structure for both the Government and the supporting contractor; Labor descriptions/categories of staffing currently supporting CIPS.

Recommendation: Provide above detail to all industry so we can more accurately predict and bid the requirement.

GOVERNMENT RESPONSE: Reference response to Question 9.

42. In PWS section 1.4.4.6, there is mention of users training. We would appreciate the following additional information:

Is there an expectation that the contractor will provide a training facility equipped with relevant hardware and connectivity?

What are the specifications for the classroom requirements (equipment, facility clearance, location, accessibility…)?

There is mention of a maximum of once a month classes for training delivered on client site or requiring travel. What is the number of classes for training delivered at contractor’s site?

How many students per classes?

Will the government provide any course material?

Will training be included in the FFP or broken out separately?

GOVERNMENT RESPONSE: Reference response to question 12.

43. Are the requirements clearly defined? RESPONSE: In general, the requirements are clearly defined.

However, we would request elaboration on the following statements:

· Section 1.4.2.5 states: “The current method for delivering this capability is to use Oracle Virtual

Machine (VM).” Can the government elaborate on how Oracle VM is currently being used?

· Section 1.4.3.1 states: “The Contractor shall provide sustainment, maintenance, operational support, and necessary documentation for CIPS system lifecycle support for all CIPS environments. This shall

Vendor Comment/Questions and Government Responses include software bug fixes and enhancements documented in the approved software lifecycle management tool. This shall also include requirements specification support, design, implementation, unit testing, integration and system testing.” The government has indicated that this is a firm-fixed price contract.

However, in order to include the fees associated with software enhancements/requirements in the proposed price, we will need to have a complete list of the type of enhancements to be undertaken. Will the government please provide such a list?

In appendices 2, 4, and 5, there are references to Oracle Label Security. Can the government elaborate how Oracle Label Security is currently being used throughout the various CIPS components?

Also what are the contractor requirements for usage or Oracle Label Security?

GOVERNMENT RESPONSE: Please refer to final PWS in RFP.

44. Comment on the use of CMMI as an evaluation standard. RESPONSE: CMMI is an excellent methodology to ensure program success. However, if the program is currently not following a standardized process, then applying a CMMI Level 2 is not only more achievable, but also would incur less management and technical overhead, while still achieving the CMMI outcome of a quality product.

While the difference between a level 2 and level 3 could be about 10-15% in man hours, it does also require management and departmental involvement that could be a burden for the government. We recommend the government consider implementing CMMI Level 2 to reduce risk and increase quality, while providing a cost saving over Level 3.

45. ADDITIONAL COMMENT: In reviewing Section L, we found the following statement which we believe requires additional clarity: Page 3; Section C, Subsection 2. SUBFACTOR 2 – Management

Approach. “Describe how for CIPS staff with all necessary security clearances and technically certified personnel to assure task coverage for the workload estimates provided to support CIPS operations.”

GOVERNMENT RESPONSE: See Section L of final RFP

46. Comment on Paragraph 3 below. RESPONSE: Considering CIPS will be an operational and development contract, T&M may provide the Air Force more flexibility to achieve their mission. If the

Air Force goes with a FFP model then tasks will need to be clearly identified to ensure the Air Force receives the desired results and the contractor is able to identify clearly the labor mix and desired delivery.

GOVERNMENT RESPONSE: The government has adequately defined the requirement and determined that the use of FFP is suitable.

47. ADDITIONAL COMMENT: Current and future labor mix has not been clarified. Please provide current/future labor mix.

GOVERNMENT RESPONSE: Reference response to Question 9

48. “Unequal Access to Information”. Awardee will have unlimited access to Government sensitive information in the performance of this requirement. Proposed Mitigation Plan? RESPONSE: We understand the importance of ensuring our customer’s mission and, at the same time, avoiding OCI issues. At the Air Force’s request, we will propose a mitigation plan that ensures the work we will be

Vendor Comment/Questions and Government Responses doing for the USAF will not interfere with other tasks. If needed, we will structure our organization to clearly separate projects that will eliminate OCI issues.

GOVERNMENT RESPONSE: Awardee will be allowed to provide mitigation plans.

50. If the Prime is not CMMI Level III, is it possible for the Prime to implement the CMMI Level III processes of their subcontractor.

GOVERNMENT RESPONSE: Reference response to Question 25

51. The original sources sought was under NAICS code 541512: COMPUTER SYSTEMS DESIGN

SERVICES, the Draft RFP is under NAICS code 517110: Wired Telecommunications Carriers. Do you anticipate the NAICS code will change?

GOVERNMENT RESPONSE: Reference response to question #21