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Airborne Software Development Assurance Using EUROCAE ED-12( ) and RTCA DO-178( )

AC 20-115D · FAA

Public domain · FAAAdvisory Circulars

Overview

The Airborne Software Development Assurance Using EUROCAE ED-12( ) and RTCA DO-178( ) (AC 20-115D) is a public-domain FAA advisory circular, republished here as a free chaptered HTML edition with a linked table of contents and the official PDF.

Publisher
FAA
Document
AC 20-115D
Pages
15
Chapters
12

Key points

  • This Advisory Circular (AC) describes acceptable means for demonstrating compliance with airworthiness regulations for airborne software systems.
  • The AC recognizes several EUROCAE and RTCA documents that provide guidance on software development and certification processes.
  • Applicants can continue using ED-12B/DO-178B processes for new software development if certain criteria are met.
  • ED-12C/DO-178C is an acceptable means of compliance for software aspects of type certification or TSO authorization.
  • The AC provides guidance for modifying and reusing software previously approved under earlier versions of ED-12/DO-178.
Frequently asked questions
What is the purpose of AC 20-115D?

The purpose of AC 20-115D is to describe acceptable means for showing compliance with airworthiness regulations for the software aspects of airborne systems and equipment.

Can I use older software development processes for new projects?

Yes, you can use ED-12B/DO-178B processes for new software development if you meet specific criteria outlined in the AC.

What documents are recognized in this Advisory Circular?

The AC recognizes several documents including EUROCAE ED-12C, RTCA DO-178C, and their respective supplements and supporting documents.

Is compliance with this AC mandatory?

No, compliance with this AC is not mandatory; it provides guidance but does not constitute a regulation.

What should I do if I want to modify legacy software?

You should follow the procedures outlined in the AC for modifying or reusing legacy software, which includes conducting a change impact analysis.

1. Purpose of this Advisory Circular (AC).

Advisory

U.S. Department of Transportation

Circular

Federal Aviation Administration Subject : Airborne Software Development Date: 0 7/21/2017 AC No: 20 - 115D Assurance Using EUROCAE ED - 12( ) and Initiated by: AIR - 134 Change: RTCA DO - 178( ) 1. Purpose of this Advisory Circular (AC).

a. This AC describes an acceptable means, but not the only means, for showing compliance with the applicable airworthiness regulations for the software aspects of airborne systems and equipment in type certification or TSO a uthorization . This AC is not mandatory and does not constitute a regulation. However, if you use the means described in the AC, you must follow it in all applicable respects.

b. This AC recognizes the following current EUROCAE and RTCA, Inc. documents : (1) EUROCAE ED - 12C, Software Considerations in Airborne Systems and Equipment Certification , dated January 2012 , and RTCA DO - 178C, Sof tware Considerations in Airborne Systems and Equipment Certification , dated December 13, 2011.

(2) EUROCAE ED - 215, Software Tool Qualification Considerations , dated January 2012 , and RTCA DO - 330, Software Tool Qualification Considerations , dated December 13, 2011.

(3) EUROCAE ED - 218, Model - Based Development and Verification Supplement to ED - 12C and ED - 109A , dated January 2012 , and RTCA DO - 331, Model - Based Development and Verification Supplement to DO - 178C and DO - 278A , dated December 13, 2011.

(4) EUROCAE ED - 217, Objec t - Oriented Technology and Related Techniques Supplement to ED - 12C and ED - 109A , dated January 2012 , and RTCA DO - 332, Object - Oriented Technology and Related Techniques Supplement to DO - 178C and DO - 278A , dated December 13, 2011.

(5) EUROCAE ED - 216, Formal Methods Supplement to ED - 12C and ED - 109A , date d January 2012 and RTCA DO - 333, Formal Methods Supplement to DO - 178C and DO - 278A , dated December 13, 2011.

Note: EUROCAE ED is hereafter referred to as ED ; RTCA DO is hereafter referred to as DO. Where the notation ED - XXX/ DO - XXX appears in this document, the referenced documents are recognized as being equivalent.

2. Applicability.

3. Cancellation.

4. Background.

5. Using ED-12B/DO-178B Processes and Procedures for New Development.

7/ 21/17 AC 20 - 115D c. This AC identifies the following as s upporting document s : ED - 94C, Supporting Information for ED - 12C and ED - 109A and DO - 248C, Supporting Information for DO - 178C and DO - 278A . ED - 94 C / DO - 248 C contains a collection of frequently asked questions (FAQs) and discussion papers (DPs) compiled and approved by the authors of ED - 12C and DO - 178C to provide clarification of the guidance cont ained in ED - 12C/DO - 178C .

d. References to use of ED - 12C/DO - 178C in this AC include use of ED - 215/ DO - 330 and supplements ED - 218 /DO - 331 , ED - 217 /DO - 332 , and ED - 21 6 /DO - 333 , as applicable.

e. This AC establishes guidance for using existing ED - 12B/DO - 178B processes fo r new development.

f. This AC also establishes guidance for transitioning to ED - 12C/DO - 178C when making modifications to software previously approved using ED - 12 /DO - 178 , ED - 12A /DO - 178A , or ED - 12B /DO - 178B .

2. Applicability. We wrote this AC for applicants, design approval holders , and developers of airborne systems and equipment containing software to be installed on type certificated aircraft, engines, and propellers , or to be used in TSO articles .

3. Cancellation. This AC cancels AC 20 - 115C , Airborne Software Assurance , dated July 19, 2013.

4. Background.

a. ED - 12C/DO - 178C , A ppendix A, section 3, provides a summary of the differences between ED - 12C /DO - 178C and ED - 12B /DO - 178B . The EUROCAE and RTCA , Inc.

documents identified in sub paragraph 1.b. of this AC provide guidance for establishing software life cycle planning, development, verification, configuration management, quality assurance and certification liaison processes to be used in development of software for airborne systems. The guidance provided in these documents is in the form of : (1) Objectives for software life cycle processes; (2) Activities that provide a means for satisfying the objectives; and (3) Descriptions of the evidence that indicate that the objectives have been satisfied.

b. The technic al content of this AC is as far as practicable harmoni z ed with European Aviation Safety Agency ( EASA ) A M C 20 - 115 D , equally based on ED - 12 C /DO - 178 C.

5. Using ED - 12B/DO - 178B Processes and Procedures for New Development .

a. Applicants who have established software development assurance processes using ED - 12B/DO - 178B may continue to use those processes (including tool qualification processes) for new software development and certification projects, provided the following criteria are met :

6. Using EUROCAE ED-12C and RTCA DO-178C.

7/ 21/17 AC 20 - 115D (1) The software development ass urance process es can be shown to have no known process deficiencies, such as those discovered during internal or external audit s or reviews , or identified in open problem report(s) resulting in non - satisfaction to one or more ED - 12B/DO - 178B objectives. Evidence of resolution and closure of all process - related open problem reports and of all process - related audit or review findings may be requested .

(2) The process es were previously used to develop software that was used in a certified product at a software l evel at least as high as the software level of the software to be developed.

(3) If m odel - based development, object - oriented technology, or formal methods will be used, existing processes incorporating these methods were evaluated and found to be acceptable by the FAA on a previous certified project . These processes should have been developed in accordance with FAA guidance specific to the technique , such as that contained in an associated issue paper or a published AC .

(4) If using configuration data , as defined under “Parameter Data Item” in ED - 12C/DO - 178C , existing processes for such data have been evaluated and found to be acceptable by the FAA on a previous certified project . In the absence of processes for using configuration data , t he applicant s hould establish new processes for using parameter data items in accordance with ED - 12C/DO - 178C .

(5) There are no significant changes to the software processes described in the plans or to the software development environment. This should be supported through analysis of changes to the previously accepted software development processes and environment.

(6) You do not intend to declare the proposed software as having satisfied ED - 12C/DO - 178C .

b. If the criteria of subparagraph 5.a. are not met, you should upgrade your processes and develop the new software using ED - 12C/DO - 178C ; t ool qualification processes should be addressed in accordance with section 12.2 of ED - 12C/DO - 178C and paragraph 10 .c of this AC .

c. Applicants or developers who are establishing new software life c ycle processes should do so in accordance with ED - 12C/DO - 178C .

6. Using EUROCAE ED - 12C and RTCA DO - 178C. ED - 12C/DO - 178C is an acceptable means of compliance for the software aspects of type certification or TSO authorization . When you use ED - 12C/DO - 178C : a. Y ou should satisfy all of the objectives associated with the software level assigned to the software and develop all of the associated life cycle data demonstrating satisfaction of the applicable objectives, as listed in the ED - 12C/DO - 178C Annex A tables and, where applicable, the ED - 215 /DO - 330 , ED - 216 /DO - 333 , ED - 217 /DO - 332 , and ED - 218 /DO - 331 Annex A tables.

You should plan and execute activities that will satisfy each objective. If the FAA chooses not to be involved in the certification l iaison process, you can consider the certification liaison process objectives and activities to be satisfied after you have produced the life cycle data specified in Table (s) A - 10 of ED - 12C/ DO - 178C , ED - 215/ DO - 330 , and supplements , as applicable.

7. Reserved.

8. Guidance applicable to ED-12B/DO-178B or ED-12C/DO-178C.

7/ 21/17 AC 20 - 115D b. You should submit the life cycle data specified in section 9.3 of ED - 12C/DO - 178C and section 9.0.a of ED - 215/DO - 330 , as applicable for tool qualification, to the appropriate project certification office. It is y ou r responsibility to perform the planned activities and produce the life cycle data necessary to satisfy all applicable objectives.

c. Section 9.4 of ED - 12C/DO - 178C specifies the software life cycle data related to the type design of the certified product. However, not all o f the specified data applies to all software levels ; specifically Design Description and Source Code are not part of the type design data for Level D .

d. You should make available to us , upon request , any of the data described in section 11 of ED - 12C/DO - 178C , applicable tool qualification data, data outputs from any applicable supplements, and any other data needed to substantiate satisfaction of all applicable objectives.

e. The FAA may publish an acceptable means of compliance for specific regulations, stating the required relationship between the criticality of the software - based systems and the software levels as defined in ED - 12C/DO - 178C . Such acceptable means of compliance will take precedence over the application of section 2.3 of ED - 12C/DO - 178C .

7. Reserved .

8. Guidance applicable to ED - 12B /DO - 178B or ED - 12C /DO - 178C .

a. U se of Supplements with ED - 12C/DO - 178C . You should apply the guidance of supplements ED - 218/DO - 331, ED - 217/DO - 332, and ED - 216/DO - 333 when incorporating the address ed software development techniques. If you intend to use multiple software development techniques together, more than one supplement applies . You cannot use supplements as stand - alone documents .

(1) When using one or more supplements, your Plan for Software As pects of Certification (PSAC ) should describe : (a) How you will apply ED - 12C/DO - 178C and the supplement ( s ) together.

(b) How you will address the applicable ED - 12C/DO - 178C objectives and those added or modified by the supplement ( s ) , which objectives from which doc uments apply to which software components, and how your planned activities will satisfy all the applicable objectives.

(2) If you intend to use any techniques addressed by the supplements to develop a qualified tool, ( for tool qualification levels (TQLs) 1, 2, 3, and 4 only) , then the Tool Qualification Plan should describe : (a) Based on supplement analysis, which tool qualification objectives are impacted by the use of the technique(s).

(b) How the planned activities will satisfy the added or modified objectives.

9. Modifying and Re-using Software Approved using ED-12/DO-178, ED-12A/DO-178A, or ED-12B/DO-178B.

7/ 21/17 AC 20 - 115D (3) The intent of this subparagraph is to provide clarification of section MB.6.8.1 of ED - 218/DO - 331 . If you are using models as defined in section MB.1.0 of ED - 218/ DO - 331 as the basis for developing software, you should apply the guidance in ED - 218/DO - 331 . When applying section MB.6.8.1 of ED - 218/DO - 331 , you should : (a) Identify what reviews and analyses objectives are planned to be satisfied by simulation alone or in combination with reviews and analyses; all other objectives should be satisfied by reviews and anal yses as described in section MB.6.3 of ED - 218/DO - 331 .

(b) For eac h identified objective, justify in detail, how the simulation activity , alone or in combin ation with reviews and analyses , fully s atisfies the specific reviews and analyses objective .

b. G uidance for Field Loadable Software (FLS) . This section supplements ED - 12C /DO - 178C and ED - 12B /DO - 178B . Use this guidance in addition to ED - 12C /DO - 178C and ED - 12B /DO - 178B when using FLS in your project.

(1) As the developer, you should provide the necessary informat ion to support the system - level guidance identified in items a, b, c and d of ED - 12C /DO - 178C section 2.5.5 ; and items a, b, c and d of ED - 12B /DO - 178B section 2.5.

(2) The FLS should be protected against corruption or partial load ing to an integrity level appropriate for the software level of the FLS.

(3) The FLS part number , when loaded in the airborne equipment , should be verifiable by appropriate means.

(4) Protection mechanisms should be implemented to prevent inadvertent enabling of the field loading function during flight or any other safety - critical phase.

c. Guidance for User Modifiable Software (UMS) . This section supplements ED - 12C /DO - 178C and ED - 12B /DO - 178B . You should use this guidance in addition to ED - 12C/DO - 178C and ED - 12B/DO - 178 B when using UMS in your project .

(1) As the developer, you should provide the necessary information to support system - level guidance identified in items a, b, c and f of ED - 12C /DO - 178C section 2.5.2 ; and items a and b of ED - 12B /DO - 178B section 2. 4 .

(2) The modifiable part of the component should be developed to a software level at least as high as the software level assigned to that software .

9. Modifying and Re - using Sof tware Approved using ED - 12 /DO - 178 , ED - 12A /DO - 178A , or ED - 12B /DO - 178B .

a. We previously approved the software for many airborne systems using ED - 12 /DO - 178 , ED - 12A /DO - 178A , or ED - 12B /DO - 178B as a means of compliance. In this AC , reference to legacy software includes the previously approved software or a component ( s ) that makes up the software used in legacy systems . In this subparagraph , we describe how to demonstrate 7/ 21/17 AC 20 - 115D compliance with the software aspects of certification for an application that includes modifications to legacy software or use of unmodified legacy software.

b. Figure 1 presents a flow chart for using legacy software. Use the flow chart while following the procedures in this subparagraph if you are modifying or re - using legacy software.

Although these procedures will apply to the majority of projects, you should coordinate situations that do not follow this flow with the certification office.

7/ 21/17 AC 20 - 115D Figu re 1 - Legacy Software Process Flow Chart Intent to use software previously shown to Conduct satisfy DO-178, DO-178A, Change Impact Analysis or DO-178B See 9.b(4) Evaluate software usage history, SDs, ADs, OPRs, etc.

Will Determine tool See 9.b.(1) there be new software qualification Yes tools or changes to tools? requirements.

See 9.b.(5) See paragraph 10.

Correct process deficiencies and Is the No No document plan for software usage history resolving related acceptable?

software deficiencies. See 9.b.(1) See 9.b.(1) Did you upgrade the Yes Yes software baseline to DO-178C IAW paragraph 9.b.(2)(a),(b),or(c)?

See 9.b.(6) Is the No software developed No using DO-178B?

See 9.b.(2) If MBD, OOT, or FM will No Yes be used, do processes support the technique IAW applicable guidance?

See 9.b.(7)(a) Is the Is the DO-178B DO-178 or Yes Yes software level DO-178A software level Yes acceptable?

acceptable?

See 9.b.(2) See 9.b.(2) Have the software plans No No No and environment been properly maintained?

Upgrade software baseline See 9.b.(7)(b) Upgrade software baseline including all processes & including all processes & procedures using DO-178B procedures using DO-178C or use DO-178C and Yes and DO-330.

DO-330.

See 9.b.(2)(a) or (b) See 9.b.(2)(c) Do you want to declare equivalence to Yes DO-178C?

See 9.b.(7)(c) Upgrade software baseline No Is including all processes & the legacy system procedures using DO-178C Yes software to be and DO-330.

modified?

See 9.b.(9) See 9.b.(3) Change software and associated life cycle data using Acronyms No the same DO-178( ) version as ADs – Airworthiness Directives the original approval. For FM – Formal Methods configuration data / PDI, use IAW – In Accordance With Change software and approved process or establish MBD – Model-Based Development Original approval basis or associated life cycle data using new process using DO-178C.

OOT – Object Oriented Technology baseline upgrade to DO-178C DO-178C, Section 12.1, and See 9.b.(8)(a) & (b) OPRs – Open Problem Reports acceptable as approval basis.

applicable supplements.

PDI – Parameter Data Item See 9.b.(3)(a) or (b) See 9.b.(6) & (9) SDs – Service Difficulties Note: References to EUROCAE documents are intentionally omitted for formatting purposes.

7/ 21/17 AC 20 - 115D (1) Assess the legacy software to be modified or re - used for its usage history from previous installations. If th e software has safety - related service difficulties, airworthiness directives, or open problem reports with a potential safety impact on the proposed installation, establish plans to resolve all related software deficiencies . Prior to modifying or reusing the legacy software, correct any related development process deficiencies, such as those discovered during internal or external audits or reviews, or identified in open problem report(s) resulting in non - satisfaction to one or more ED - 12B/DO - 178B objective s. Evidence of resolution and closure of all process - related open problem reports and of all process - related audit or review findings may be requested.

(2) The system safety process assigns the minimum development assurance level based on the severity classif ications of failure conditions for a given function. The ED - 12B/DO - 178B software levels are consistent with the ED - 12C/DO - 178C software levels. However, ED - 12 /DO - 178 and ED - 12A /DO - 178A were published prior to establishment of the levels addressed in ED - 1 2B /DO - 178B and ED - 12C /DO - 178C . Use Table 1 to determine if your legacy software level satisfies the software level assigned by the system safety process for the proposed installation. A “  ” in the intersection of the row and column indicates that the legacy software level is acceptable. For example, legacy software with development assurance to ED - 12A/ DO - 178A Level 2 can be considered to satisfy software Levels B, C, and D. A blank indicat es that the software level is not acceptable. Therefore, the ED - 12A/DO - 178A software developed to Level 2 would not be acceptable where software L evel A is required.

Table 1 – Software Level Relationships Legacy Legacy Legacy Software Level Software Level Assigned Software Level per ED - 12B/ per ED - 12A/ Software per ED - 12/ DO - 178 DO - 178B DO - 178A Level Non - A B C D 1 2 3 Critical Essential Essential A    B      C        D         (a) If your legacy software was developed to software Level Essential using ED - 12/ DO - 178 and was previously accepted by the certification authority as acceptable for software Level B, it remains acceptable for the new project. If the ED - 12/ DO - 178 legacy software was not previously assessed, or the software level is not acceptable, upgrade the software development baseline, including all processes and procedures (including tool qualification processes), using section 12.1.4 of ED - 12C/DO - 178C , and ED - 215/DO - 330 .

(b) If your legacy software was developed using ED - 12A/ DO - 178A, and the software level is not acceptable, upgrade the software development baseline, including all 7/ 21/17 AC 20 - 115D processes and procedures (including tool qualification processes), using sect ion 12.1.4 of ED - 12C/DO - 178C , and ED - 215/DO - 330 .

(c) If your legacy software was developed using ED - 12B/DO - 178B , and the software level is not acceptable, upgrade the software development baseline, including all processes and procedures (including tool qualification processes), using section 12.1.4 of ED - 12B/DO - 178B or ED - 12C/DO - 178C and ED - 215/DO - 330 .

(3) If the crite ria in subparagraphs 9(b)(1) and 9(b)(2) are satisfied and modifications to the software are not required, then : (a) The original approval may serve as the basis for the software in the installation approval of the proposed system.

(b) If you upgraded the software development baseline using ED - 12C/DO - 178C and updated all processes and procedures, including tool qualification processes, to ED - 12C/DO - 178C and ED - 215 /DO - 330 , then you may declare your software as equivalent to satisfying ED - 12C/DO - 178C . However, you c annot declare your unmodified tools as equivalent to having satisfied ED - 12C/DO - 178C and ED - 215/DO - 330 . All subsequent modifications to all your software and tools are to be made using your processes and procedures that satisfy ED - 12C/DO - 178C and ED - 215/DO - 330 .

(4) If modifications to the software are required, conduct a software change impact analysis (CIA) to determine the extent of the modifications , the impact of those modifications, and what verification is required to ensure that the modified sof tware performs its intended function and continues to satisfy the identified means of compliance.

(a) Identify the software changes to be incorporated and perform a CIA consisting of one or more analyses associated with the software change as identified in sec tion 12.1of ED - 12C/DO - 178C ; (b) Conduct the verif ication as indicated by the CIA; and (c) Summarize the results of the CIA in the Plan for Software Aspects of Certification (PSAC) or in the Software Accomplishment Summary (SAS).

(5) If new software tools or modificati ons to tools are needed, refer to paragraph 10 of this AC to determine tool qualification requirements.

(6) If you upgraded the software baseline to ED - 12C/DO - 178C in accordance with subparagraph 9.b.(2), make all modifications to the software using section 12 .1.of ED - 12C/DO - 178C . If you want to declare your software as equivalent to satisfying ED - 12C/DO - 178C , your equivalence declaration applies to both modified and unmodified software and is valid even if you use unmodified tools that have not been qualified using ED - 12C/DO - 178C . However, you cannot declare your unmodified tools as equivalent to having satisfied ED - 12C/DO - 178C and ED - 215/DO - 330 . All subsequent modifications to all your software and tools are to be made using your processes and procedures th at satisfy ED - 12C/DO - 178C and ED - 215/DO - 330 .

10. Tool Qualification.

7/ 21/17 AC 20 - 115D (7) If you want to use your existing processes to make modifications to your legacy software using the version of ED - 12 ( ) /DO - 178 ( ) ( i.e . , ED - 12 /DO - 178 , ED - 12A /DO - 178A , or ED - 12B /DO - 178B ) that was used for the orig inal software approval, you may do so provided all of the following conditions are met : (a) If m odel - based development, object - oriented technology, or formal methods will be used, existing processes incorporating these methods were evaluated and found to be acceptable by the FAA on a previous certified project . These processes should have been developed in accordance with the FAA guidance specific to the technique, such as that contained in associated issue paper or published advisory circular .

(b) You have maintained, and can still use, the software plans, processes, and life cycle environment, including improvements to processes or to the life cycle environment as captured in revised plans .

(c) Yo u do not intend to declare the proposed software as having satisfied ED - 12C/DO - 178C .

(8) If the conditions in subparagraph 9.b.(7) are satisfied : (a) Y ou may accomplish all modifications to the software using the same ED - 12()/ DO - 178( ) version as the original app roval. However, you may not declare your software as equivalent to satisfying ED - 12C/DO - 178C .

(b) If using configuration data , as defined under “Parameter Data Item” in ED - 12C/DO - 178C , you may use existing processes for such data if the processes were evaluat ed and found to be acceptable by the FAA on a previous project . In the absence of processes for using configuration data , you should establish new processes for using parameter data items in accor dance with ED - 12C/DO - 178C .

(9) If any of the conditions in subparagraph 9.b.(7) are not satisfied, update all your processes and procedures (including tool qualification processes), using ED - 12C/DO - 178C and ED - 215/DO - 330 , and make all modifications to the software using section 12.1 of ED - 12C/DO - 178C . If you want to declare your software as equivalent to satisfying ED - 12C/DO - 178C , your declaration applies to both modified and unmodified software and is valid even if you use unmodified tools that have not been qualified using ED - 12C/DO - 178C and ED - 215/DO - 330 .

Howe ver, you cannot declare your unmodified tools as equivalent to having satisfied ED - 12C/DO - 178C and ED - 215/DO - 330 . All subsequent modifications to all your software and tools are to be made using your processes and procedures that satisfy ED - 12C/DO - 178C an d ED - 215/DO - 330 .

10. Tool Qualification. Section 12.2 of ED - 12C/DO - 178C , and ED - 215/DO - 330 provide an acceptable method for tool qualification. ED - 215/DO - 330 contains its own complete set of objectives, activities, and life cycle data for tool qualification .

a. If your legacy software was previously approved using ED - 12 /DO - 178 or ED - 12A /DO - 178A , and you intend to use a new or modified tool for modifications to the legacy software, use the criteria of section 12.2 of ED - 12C/DO - 178C to determine if tool qualifica tion is needed. If 7/ 21/17 AC 20 - 115D you need to qualify the tool, use the software level assigned by the system safety assessment for determining the required Tool Qualification Level (TQL) , and use ED - 215/DO - 330 for the applicable objectives, activities, and life cycle data. You may declare your qualified tool as having satisfied ED - 215/DO - 330 but not the legacy software as equivalent to having satisfied ED - 12C/DO - 178C .

b. If your legacy software was previously appr oved using ED - 12B/DO - 178B , and you do not intend to declare equivalence to satisfying ED - 12C/DO - 178C , you can either: (1) Use your ED - 12B/ DO - 178B tool qualification processes for qualifying new or modified tools in support of modifications to ED - 12B/ DO - 178B le gacy software , or (2) Update your tool qualification processes and qualify the tool using ED 215/DO - 330; use Table 2 of this document for determining the required TQL. You may then declare your qualified tool as having satisfied ED - 215/DO - 330 .

c. If your legacy software was previously approved using ED - 12B/DO - 178B , you intend to declare equivalence to satisfying ED - 12C/DO - 178C , and you have ED - 12B/DO - 178B legacy tools that need to be qualified, follow the guidance of this subparagraph.

(1) ED - 12C/DO - 178C establishes five levels of tool qualification based on the tool use and its potential impact in the software life cycle processes (see section 12.2.2 and Table 12 - 1 of ED - 12C/DO - 178C ). However, ED - 12C/DO - 178C does not address the use of tools previously qualified to the ED - 12B/DO - 178B criteria. For a tool previously qualified as a ED - 12B/DO - 178B development tool or verification tool, use Table 2 (below) to determine the correlation between the ED - 12B/DO - 178B tool qualification type and ED - 12C/DO - 178C too l criteria and tool qualification levels (TQLs).

Table 2 - Correlation Between ED - 12B/DO - 178B Tool Qualification Type and ED - 12C/DO - 178C Tool Criteria and TQL ED - 12B/ ED - 12C/ ED - 12C/ED - 215 Software DO - 178B Tool DO - 178C DO - 178C/DO - 330 Level Qualification Type Tool Criteria TQL Development A 1 TQL - 1 Development B 1 TQL - 2 Development C 1 TQL - 3 Development D 1 TQL - 4 Verification A, B 2 TQL - 4 Verification C, D 2 TQL - 5 Verification All 3 TQL - 5 (2) Development Tools Previously Qualified Using ED - 12B/DO - 178B .

12. Where to Find this AC.

7/ 21/17 AC 20 - 115D (10) RTCA DO - 333, Formal Methods Supplement to DO - 178C and DO - 278A, dated December 13, 2011.

(11) EUROCAE ED - 12, Software Considerations in Airborne System s and Equipment Certification, dated May 1982 (no longer in print).

(12) EUROCAE ED - 12A , Software Considerations in Airborne Systems and Equipment Certification, dated October 1985 (no longer in print).

(13) EUROCAE ED - 12B , Software Considerations in Airborne Systems and Equipment Certification, dated December 1992.

(14) EUROCAE ED - 12C , Software Considerations in Airborne Systems and Equipment Certification, dated January 2012.

(15) EUROCAE ED - 94C, Supporting Information for ED - 12C and ED - 109A, dated January 2012.

(16) EUROCAE ED - 215 , Software Tool Qualification Considerations, dated January 2012.

(17) EUROCAE ED - 218 , Model - Based Development and Verification Supplement to ED - 12C and ED - 109A, dated January 2012.

(18) EUROCAE ED - 217 , Object - Oriented Technology and Related Techniques Supplement to ED - 12C and ED - 109A, dated January 2012 (19) EUROCAE ED - 216 , Formal Methods Supplement to ED - 12C and ED - 109A, dated January 2012.

12. Where to Find this AC.

a. You may find this AC at http://www.faa.gov/regulations_policies/advisory_circulars/ .

b. If you have suggestions for improvement or changes, you may use the template at the end of this AC.

Susan J. M. Cabler Manager , Design , Manufacturing, & Airworthiness Division Aircraft Certification Service 7/ 21/17 AC 20 - 115D Appendix A Appendix A. Advisory Circular Feedback Information If you find an error in this AC, have recommendations for improving it, or have suggestions for new items/subjects to be added, you may let us know by (1) complete the form online at https://ksn2 .faa.gov/avs/dfs/Pages/Home.aspx or (2) emailing this form to 9 - AWA - AVS - AIR - DMO@faa.gov Subject: AC Date: ___________ Please check all appropriate line items: An error (procedural or typographical) has been noted in paragraph _______ on page _______ .

Recommend p aragraph _______ on page _______ be changed as follows: In a future change to this AC, please cover the following subject: (Briefly describe what you want added.)

Other comments: I would like to discuss the above. Please contact me.

Submitted by: _______ ___________________________ Date: __________________ Telephone Number: __________________ Routing Symbol: _________________ FAA Form 1320 - 19 (10 - 98) A - 1

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Document details

Doc number
AC 20-115D
Publisher
FAA
Pages
15
File size
499 KB
Chapters
12