The methodology depends on many factors: the context in which it conducts creative activity, the intended application of the results, the time available, the proper object design, the lens ( educational or not) , depth that is to work , motivation of developers, the academic year ( prior knowledge) , etc. I do not think there is one method for all, but I think any basic design methodology can be adapted from different creative techniques . Any projection of a problem well defined , deny antedecedentes take these valuable, identify requirements , conceptualize, develop alternatives , specific the better, to test it , adjust, etc. How to achieve this ? We recommend that you study the situation in each case and not follow recipes.

Concerning the activities, I agree with the previous reactions that almost any creativity technique is helpful here. Roozenburg and Eekels in Product Design: Fundamentals and Methods 1995 have an extensive list of creativity methods that I find very valuable. There is no One-Method-Fits-All. You need to develop a sensibility when each creativity technique is most suitable. A way for formulate such an approach could be based on Donald Schon's (The Reflective Practitioner, 1983) cycle of Naming-Framing-Moving and Reflecting. Naming determines the most important issues to be solved, Framing would be your strategic choice of techniques, Moving executing the techniques, and Reflecting the consideration and evaluation of the effectiveness of that application.

Filippo Salustri's suggestion of Christopher Alexander's seminal book, Notes on the Synthesis of Form, is a cracking one. I based my PhD thesis on the work of Alexander, albeit for slightly different reasons. I have had a book published recently with Laurence King Publishers, London entitled Research Methods for Product Design that includes many methods for facilitating creativity, generating ideas, analysing ideas and communicating those ideas to others. You can find the book on Amazon here - http://www.amazon.co.uk/Research-Methods-Product-Design-Portfolio/dp/1780673027/ref=sr_1_1?s=books&ie=UTF8&qid=1422519406&sr=1-1&keywords=research+methods+for+product+design

The methodology which evolved for the students of architecture at the Ecole Des Beaux Arts in Paris (training institution for all government architects which was finally closed in 1968) was a 3-part process:

Parti ('Decision') a very small sketch which embodied all the important aspects of an architectural design in (usually) a single plan, section, and, if possible, elevation; plan and section were the only two requirements.  This was usually done to approximate scale, and often freehand.  Students had to submit the parti and then adhere to it during later stages of design development.  It was often done in a controlled environment (limited time frame under supervision) so that the authorship of the work could be verified.

Esquisse ('Sketch') development to scale of all important plans sections and elevational treatments.  This was drawn to scale and usually involved the use of tools and wash to convey accurate dimensions and some idea of volumetrics.

Rendu ('Rendering' or 'Submission') full architectural design from which , in theory, construction drawings could be developed.  These usually included representative  construction details and sometimes a composite drawing (Analytique) which engaged all the important formal elements of the design philosophy behind the project in sufficient detail for a juror to comprehend the intellectual content of the design intent.  This would usually have been presented in the form of fully rendered orthographic projections, although perspective and even isometric/axonometric views were not unheard of by the early 20th century. To be eligible for review, these big elaborate presentations were collected on a cart into which sometimes the student jumped in order to put on the finishing touches, from which the term 'en charette' (working up to the last minute before the project is due) comes.

It s important to note that this process took place in two contexts:  one was that of the Ecole itself, which was founded during the administration of Louis XIV as an instrument of state policy in which all the visual arts including painting and sculpture were associated in the same school.  Over time instruction about the nature of architecture was informed by research in archaeology, philological analysis, scientific engineering, and historiography including, later in the 19th century, cultural history and ethnography.  Drawing conventions of the time were limited to hand work, but the medium changed from opaque paper and ink (line and wash) to translucent tracing paper (for design studies) and watercolour.  Important teachers were responsible for course curriculum, but students were also assigned to the studios of important practitioners (themselves always graduates of the Ecole) for practical experience during their studies.

The other context was that of the Concours ('Competition') in which all students of a particular practitioner were assigned the same brief and site for a given design exercise.  Submissions were made anonymously and judgement was done privately (i.e., without the students being on hand to witness the review) and rankings were complied on a nominally impersonal basis.  In fact, once a student had experience with the Ecole, his design style would likely be recognised and a certain amount of favouritism was probably inevitable.

These two contexts of course survived the Ecole and serve as the basis of present day teaching in architecture, especially since the method of the Ecole was particularly taken up in the United states from the late 1890s and many important practitioners had some experience with the Ecole; later the important professional schools (e.g. MIT, of which Marion Mahoney Griffin was a graduate, Harvard, Yale, Princeton, University of Pennsylvania) adopted a simplification of the Ecole approach in training architects..  Then as now the aim was to produce competent professionals and artists of incisive vision, and our professional categories of 'Schematic Design', 'Design Development', and to a certain extent 'Contract Documentation' track the 3-part submission process of the Ecole. 

Design is related to the creative process of producing new items and solve problems through communication also occurs through various means and ways.

The activities recommended for the design of the full extent are more related to the forms of reasoning logically accompanied knowledge of the final design process as it is: the object, service, environment and others.

As the observation, research, analysis, adjustments, modeling (analog and virtual) productions, large: the importance of all the visual elements of communication are helping to spread the design itself is noteworthy works both engineering and architecture; in short The design process is considered a complex and highly subjective activity where good interaction and group discipline will be critical to obtain excellent results.

Perhaps some remarks are in order about unexpected outcomes of the so called 'Beaux Arts' method in architectural design.

At the University of Pennsylvania the method survived longest in the USA, and the student works of Louis I Kahn (d 1974) dating from as late as 1936, are fully developed exercises showing the above methodology.

Charles Eduoard Jeanneret, aka Le Corbusier (d 1965) , never attended the Ecole but his earliest works might be considered a Franco/Suisse expression of 'Arts and Crafts' with his last pre-WW1 work tending towards a classical idiom which would have been suited to contemporary work at the Ecole.  He remained a lifelong foe of the Ecole and, as he termed it, 'l'academisme'.  

Henry Hobson Richardson (d1886) attended the Ecole in the 1860s, possibly to escape war duty in the USA (he was a native of Louisiana).  His autograph drawings track the 3-part Ecole system during his entire career, which was extraordinarily successful and influential.  His own practice, centred in Boston, was modelled on the system of 'patronage' (Patron= 'Boss') in the professional ateliers of the Ecole in which students gained practical experience, and enjoyed a degree of prestige that the most celebrated French architects of the time also shared.  Most interestingly, for publication of his works, Richardson usually insisted on the medium of photography, a rare and expensive process at that time with which he had become familiar in Paris.  His unique 'Romanesque' interest was stimulated by de Vogue's archaeological compendium Syrie Centrale which was a new publication at the time.

Raymond Hood (d1934) attended the Ecole before WW1 and had an extraordinarily successful career in the USA designing the competition-winning and constructed Chicago Tribune Tower, the New York Daily News Building.  Hood later went on to serve on the design team for Rockefeller Centre.  One of his last and most interesting works is the art-moderne McGraw Hill building on West 42nd Street, Manhattan, entirely clad in continuous horizontal spandrels of malachite green glazed terracotta tile with vermilion red window mullions.

Certainly inspiration in architecture can come from many sources and this is no where more completely demonstrated than in the careers of those trained at the Ecole and even those who might have enjoyed the recognition of having done so but had to content themselves to learning from afar.

as a PS to the above:  

As a Swiss national, Jeanneret probably would not have been eligible for French government work in any case. After he moved to Paris his clients were wealthy industrialists and private developers.

But Tony Garnier (d1948) was eligible,  and attended the Ecole, receiving the Prix de Rome (the architecture school's most important award) in 1899.  In 1905 he published his 'Cite Industrielle', which, though not realised, was and is seen as a fore runner of functionalism in architecture.  

Project design methodology is a though matter. It relates to the question of election of Form.

On the matter of form election I would recommend the wonderful discourse by Rafael Moneo on arbitrariness (Rafael Moneo, Sobre el concepto de arbitrariedad en arquitectura, Madrid: Real Academia de Bellas Artes de San Fernando, 2005).

On the other hand, Aldo Rossi defined in his text about Boulle that the act of creation responds to a personal obsession. He wrote of exalted rationalism as the one which, within a rational method, resorts to a process of choice of formal reference that allows the passage from the abstract concept to the concrete idea through the intervention of personal choice based on an autobiographical reference of the architect. Consequently, he resolved both the fact of the permanence of history, and forms, in the collective imagination as the need for a personal choice of the author regardless of the existence of a rational and communicable method linked to the act of designing, establishing thus a necessary theory of projection (Aldo Rossi, ‘Introduzione a Boullée’, in Scritti scelti sull’architettura e la città, Milano: Cooperativa libraria universitaria del politecnico, 1975, pp. 346-364) This text proposes a project design methodology that explains the autobiographic origin of architectural concepts.

Rossi also argued that "the formation of a theory of projection is the specific objective of a school of architecture, and its priority, above all other research, is incontestable. A theory of projection represents the most important, fundamental moment of all architecture, and therefore a course of projection theory should be placed as the main axis of the schools of architecture" (Aldo Rossi, ‘Architettura per i musei’, in Scritti scelti sull’architettura e la città, Milano: Cooperativa libraria universitaria del politecnico, 1975, pp. 323-339). Unfortunately these theories are rare nowadays.

Architectural design is a Cultural problem solving matter.

All activities concerning design areas require a creative spirit. When you have to develop the basic or guiding idea in the creation of spaces, creativity plays a very important role; Likewise, there are processes that help improve creativity. They are based on activities that have to be developed in a systematic way in order to see their results. An example: Flexibility, if you are not flexible you cannot transcend that special idea that makes your project unique. Likewise tolerance for ambiguity. Understand what is different, but in the case of ARCHITECTURE, the creative act must be accompanied by the responsibility of the structural.

I recommend works of Edward Necka - a psychologist of creative processes. He has a profile here on RG.

Dubberly Design Office website - http://www.dubberly.com - has a great list of design models and concept maps that you can draw upon.