Friday, December 2, 2011


Post -by Gautam Shah

Specifications derive their importance and relevance on How and Where these are presented. Specifications in Design Practice are placed in many different types of documents with peculiar formats to serve very exact intentions. The Document type, location (Placement) and the format of presentation, are all determined mainly by the nature of exposure the specifications are to have.

Document types: Design documents are essentially of Four types: in-house, clients’ eyes, for consultant’s and for job award or execution. Other minor varieties of design documents include: for public presentation, for government authorities.
Location or Placement: Specifications are placed in sketches, drawings, as write-up accompanying drawings, as part of Job awards, brief memos, long reports, signage, as product or packing labels.
Format of Presentation: Specifications are literary or worded, drawn, orally communicated. Specifications could be sketchy, detailed, independent and intricately linked. Specifications could be drawn, printed, digital, audio-video, signs, signals, original, facsimiles.
Exposure: Very personal, i.e. author's-eyes only (access restricted to its creator), In-house (available to office-staff only), Clients’ reference, Consultants' assignments, Bids invitations or Job awards, Contract documents, Operating agencies.
Contents: The contents of specification documents are often defined to serve very specific purposes. The contents are re validated to see if, the information is private vs. public, Data is freehold (public domain) or patent (copyright, intellectual property), subject is prosaic or engaging, presentation is brief or detailed, language is allegorical or straightforward, etc. 

Within a sketch or preliminary drawing: These drawings are prepared to initiate an idea. Sketch or preliminary drawings are too small in scale, lacking in details, and do not carry all the graphical views to convey the intentions. Similarly materials, components, procedures, and design parameters which have not yet been fully conceived, or not crystallized into a formal structure, are all placed as a write-up. Such write-ups are usually meant for the designer's personal reference, and very rarely for the client, so need not be a trade, technique or material specific. These write-ups may be just indicative or thin in content, as these are seedlings from which the total idea is to germinate.
Within a schematic drawing: At a schematic drawing's stage, the design has taken shape. Options regarding materials, finishes, techniques, are explored and indicated as write-up, in the drawing. Where parts / subsystems are yet to be conceived their design parameters are also indicted. More often than not a set (copy) of schematic drawings is submitted to the client. In such a case only the office copy (in-house set), carries the specifications’ write-up. Schematic drawings are exploratory so may also carry optional specifications. However, whatever is shown or implied, will be construed by a client to be a promise.
Within a Layout Drawing: Layout drawings as the name indicates are used for specifying the whole work. These are also used in laying out the work on a site, and so contain specifications for establishing the scheme on the site. Since this is the main or starter drawing it establishes links to other drawings and details. It is used for conveying methods of interpretation for this and other linked drawings. Measures (dimensions, tolerances, fitments, margins, and measures like weights /mass /speed /time), which cannot be graphically indicated or linked to any particular graphical view are presented as a common write-up or explanation. Being the basic drawing, it provides a common ground to indicate, when and how a part or parts of drawing become execution worthy. Limitations and responsibilities of various agencies' work, time schedules and inter linkups for start and completion of various items, parts, etc., are all specified in the layout drawing.
Within a Detail Drawing: Detailed drawings are generally large scale presentations of complex parts. These drawings are often used by several trades’ persons. Overlapping areas of several components are shown here. The detail drawing specifications include legends showing graphical vocabulary used for identifying various materials in sections and on their faces (elevations). It also includes graphical symbols to represent very small parts or standard components. The specifications on such drawings clearly indicate or establish relationships between the component and the concerned trades branch. Where several detailed drawing sheets are referred for a part or component, specifications need not be repeated on all sheets. However, if specifications are to be distributed over several sheets, a proper linkage must be established. These makes it easy to revise specifications or drawings, and convey such changes to the concerned parties, through other means of communications.
Within a Component Drawing: Components are conceived as self sufficient sub systems, and as a result their details consist of not only the fitment conditions, but operative parameters as well. Component specifications generally do not spread over to many drawings (Large/complex components will consist of sub assemblies, which can be detailed individually). Components, if presented with siting specifications, it will mean a non standard placement is proposed. Whereas for standard components, absence of siting specifications, will mean that standard conditions apply. Standardized components may also be indicated by referencing the Standards’ Documents.
 As a separate write-up but on the Drawing Sheet: Specifications as a separate write-up on drawings, generally relate to procedures and materials about several parts or whole of the object, e.g. siting of a building on land, preliminary-work to be carried out before the commencement of actual work, precautions regarding the start / continuation / completion of the work, etc. These are presented in a written format, because graphical formats are inadequate or inappropriate here. In situations where graphical presentations are likely to create ambiguities in interpretation (as in a court of law, or by lay people not conversant with graphical presentations, communication through inappropriate modes, etc.) details must be additionally specified in writing.
As a separate document accompanying Drawings: Where Specifications are not related to any particular drawing, and are describing common materials and procedures etc. that generally relate to the entire work, and when are very lengthy, are supplied on separate sheets of paper accompanying the drawing. If necessary, mention of such Sheets is made in the relevant drawings. Such sheets sometimes are bunched together as a catalogue of Specifications of Works.
As Memos and Short Messages: Site and Design Office have a continuous exchange of messages relating to inquiries, clarifications, confirmations, rejections, acceptance, corrections, reporting, etc. Some sections of such communications could have effect equal to a revision of a specification or initiation of a new specification. For this reason all messages, routed through whatever mode of communication must be Dated and Numbered with Author and Receiver's Identity. It is often more prudent to separate out Communications that could have Consequential Effect, and reconfirm them in the weekly or periodical reports. Communications relating to a specification, must mention the relevant part, component, subsystem or section of the project and exact location (drawing, communication, tender etc.) where it was earlier referred to.

 As part of the Job Award Document like Tender: Specifications are very often linked to the Quantities of various tasks or work items, by actual mention or sheer proximate placement. The contractor is than asked to quote for the items. Such specifications are divided into two classes:
General Specifications: General Specifications as the name suggests, relate to the whole of work or several items. These are subdivided into categories such as (a) materials (b) techniques / procedures (c) precautions (d) time schedules (e) mode of measurements (f) billing procedures (g) completion of a part/s or whole.
Special Specifications: Special Specifications relate to an item and its materials, techniques / procedures, precautions, time schedules, etc. Such specifications are sometimes trade or supplier specific, and as a result, are restricted and technical in nature. Often the supplier is allowed to offer own improvised scheme within the frame work of specifications. Such specifications instead of describing, how and with what a part is to be made, a list of Performance Parameters and Conditions of Fitments are provided.
When specifications occur with any quantities for work or job, these are often perceived by the contractor or vendor, to be the optimal quantity of work for cost calculation. To avoid such a perception minimal quantity per natural lot of work (e.g. RCC or masonry work per day or stage) may need to be indicated.
As a Public Declaration: Public organizations are required to be transparent in their dealings. Public organizations regularly or occasionally (synchronized with major endeavours) place a statement in a public domain. This could be legal requirement, tradition or a voluntary act. Such a declaration in the form a Statement of Work (SOW), is published when a new project is launched. It could also be an internal publication for all stack holders or one handed over to the contractor of a project.
As Description for Pro-forma Invoice: To avoid the technicality of specifications writing, many organizations, prefer to acquire items that are familiar, standardized or commonly available in the market. Commercial descriptions or simply the Brand Names are provided as a Pro-forma Invoice (an advanced bill / predefined bill). Such Pro-forma Invoices also include the conditions of delivery, installation, the quantity, sizes along with the tentative rates. Often the buyer indicates a tentative rate over which a supplier provides a quote which may be lower, equal or higher. Such a system obviates several office procedures. The Pro-forma Invoice Specifications in a way demand a particular product or its equivalent, with knowledgeable performance. Pro-forma specifications do not allow any revision of specifications.
Referencing Standards: Specification to be compact, reference Published (public domain) Standards. Most Standards for part or detail level clarity refer to many other standards. So when a standard publication is referenced only by its title and code (and by not quoting its text), intentionally the main standards document is attached, but unintentionally other linked standards also automatically getting attached. A sub condition of a standard may be referenced, but it is very difficult to make it really effective bereft of its natural attachments.

Thursday, December 1, 2011


 Post -by Gautam Shah 
General: Performance Specifications tell a manufacturer, vendor, supplier or provider: What is considered to be an acceptable product? And How will the product's acceptability be judged ? In other words performance specifications state requirements in terms of the results to be achieved and provide criteria for verifying the compliance. Such specifications define the functional requirements for the product, the environment in which it must operate, and the interface and interchangeability requirements. Performance specifications, however, do not state means or methods for achieving the results. It allows the supplier with freedom to not only choose but improvise materials and methods.

Systems specifiers like a designer deal with a product or system only occasionally and do not get frequent feedback. Whereas a system provider (such as the supplier, manufacturer, fabricator or installer) is consistently involved in supply field, and receives feedback from diverse sources. System suppliers as a result has better understanding and capacity to improvise the product. A system specifier may specify a technologically adequate system, but a system provider offers a technologically superior and economically most appropriate item.

A designer as a system specifier must work in close collaboration with the markets (represented as the supplier, manufacturer, fabricator or installer, etc.). To specify performance, ideally a system specifier and the parties capable of submitting the proposal or bid, both must have a consensus as to what the requirements are. But this type of neutral interaction is not possible or desirable in Government deals. So it is desired that requirements of performance are specified quantitatively rather than qualitatively. Qualitative data can provide varying interpretations and cause misunderstandings, but quantitative data is easily verifiable.

Performance and Verification: Any condition, characteristic, or capability that must be achieved, and is essential for item to perform in the perceived environment must be plausible and verifiable. For example, if a building is required to withstand certain measure of an earthquake, then methods how to verify this must be stated. Verification process is accompanied by definition of 'the extent of contractor or vendor's participation and their liability for providing corrective solution’. Warranties offered by the vendor can to some extent substitute the performance and verification requirements. However, very often warranties of the vendors are restricted to their own supplies. The warranties are also conceived like a risk management system for compensating a fault with something 'equivalent' or money, but not the for the affectations that occur in adjacent areas or systems.

In comparison to item or work specifications, performance specifications require fewer references, except for standard tests, interface drawings, etc. Due to the absence of procedures, performance specifications are less dependent.

Restrictions in Performance Specifications: Performance specifications must not limit a provider to specific materials, processes (including quality of man power or equipments), parts, etc. However, one can prohibit certain materials, processes, or parts when authorities have declared quality, reliability, or safety concerns such materials, technics or processes, as for example environmentally harmful technologies. Upper and/or lower performance characteristics can only be stated as requirements, but not as goals or best efforts.

Writing performance specifications: A System specification writer must know: ‘Which requirements are absolute or threshold requirements? Definitions of such thresholds. All constraints governing operations or use through natural and induced environments, interface with other systems, operator and maintenance person's limitations, must be declared’‘.

Performance Specifications for Structural, Architectural and Interior Design jobs: Such jobs consist mainly of industrially produced and standard components, but their composition (fabrication, installation or siting) is a unique phenomenon. Performance specifications at parts or components level are not very difficult to implement. However, adopting a performance specification strategy for large complex systems, or whole projects is a very difficult proposition. Design professionals can overcome this problem by consciously moving towards self-sufficient systems like plug-in modules, rather then excessively customised products that remain one-time efforts. Performance specifications at lower levels such as for replaceable components and spares, should include essentials for interchangeability and interoperability.

Strategies for Creating Performance Specifications: It is very difficult to conceive a fresh set of exclusive performance specifications. But one can gradually and consciously reformat the traditional specifications with inclusion of performance parameters for standard parts and components.

Resources for Performance Specifications: Many resources are available to form performance specifications, such as: Government departments and large corporate groups which prepare indexed descriptions of commercial items for frequently or routinely required products. Such performance oriented descriptions are available in a public domain through their purchase bids. Trade associations, commercial organizations, or technical societies often develop coordinated standard specifications, for the warranted performance of items produced by their members. Government Departments design and publish Model Specifications for use by their own sub departments and other agencies. Performance specifications of well-organized departments like defense, telecommunications, etc. can be used for further understanding of the methodology. Market analysis as available in technical journals can show the ranges of performance that are currently possible. Market analysis also show the technologies involved and available alternatives.
Standard Performance Specifications: Standard performance specifications are intended to facilitate standardization and interchangeability of common equipment. Standard performance specifications specify product characteristics, dimensions, matters relating to form, fit, and functions.


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