Sketch design is developed when it is stipulated in technical specifications or in the protocol of technical proposal review.
Sketch design is worked out with the aim of making the main (constructive, schematic etc.) solutions for the product that give a general idea about the principle of product operation and (or) structure, when it is reasonable to do this before technical design or working documentation development.
At the stage of sketch design development it is possible to consider the product variants and (or) its component parts, system elements, fitting elements etc.
During the sketch design development, the works that are necessary to fulfill the product specified requirements and that enable to make principal solutions are performed. List of required works is determined by the Designer depending on product type and intended use, and if necessary, it is agreed with the Customer.
Note. At the stage of sketch design development, the works specified at the stage of technical proposal are not repeated, if there are no additional data. In this case, the results of performed works are recorded in the explanatory note.
The set of sketch design documents includes the design documents stipulated in technical specifications and technical proposal.
Requirements to documents execution
General view drawing
General view drawing of sketch design must generally contain the following:
а) product images (views, sections), text part and inscriptions required for understanding the product (system, unit) design arrangement, interaction of component parts and principle of product operation;
b) names and designations (if there are any) of those component parts, for which the data (technical characteristics, quantity, material, operation principle and others) should be specified, or whose record is necessary for explanation of the general view drawing images, product operation principle description, elements indication etc.;
d) diagram, if required;
e) product technical characteristics, if necessary.
Sketch design list
All design documents included into the set of sketch design documents are recorded into the sketch design list.
а) section “Introduction” contains the name, the number and the date of technical specifications approval. If the development of sketch design is stipulated in the protocol of technical proposal review, then the number and the date of the protocol of technical proposal review are specified;
b) section “Intended use and application field” contains the respective information from technical specifications and technical proposal.
c) section “Technical characteristics” contains:
- product main technical characteristics (for example, consumable power, number of revolutions, refrigeration capacity, consumption of electric power and fuel, efficiency factor and other parameters that characterize the product);
d) section “Description and justification of selected design” contains:
- design description, reasons for the principal (constructive, schematic etc.) solutions made at this stage.
e) section “Estimations that prove the design serviceability and reliability” contains:
- rough estimations that prove the design serviceability (kinematic, electric and thermal estimations, hydraulic systems estimations etc.);
- rough estimations that prove the product reliability (life, maintainability, preservation capacity estimations and others).
f) section “Description of works arrangement using the product under development” contains the preliminary information about works arrangement with the product at site including:
- description of work methods and procedures in modes and conditions specified in the technical specifications;
- description of methods and procedures of product transportation, mounting, storage and its startup at site as well as maintenance during storage and operation;
- information about attending personnel qualification and number of personnel;
g) section “Expected technical-and-economic indexes” contains the rough estimations of economic indexes;
h) section “Level of standardization and unification” contains the preliminary information about the use of standard, unified and adopted assembly units and parts for the product under development.
List of works performed during the development of sketch design
The following works are generally carried out during the development of sketch design:
a) implementation of possible solutions variants, specifying of variants features (characteristics of component parts variants etc.), their design study.
b) preliminary solution of issues concerning the product packaging and transportation;
c) manufacturing and testing of models to check the product and (or) its component parts operation principles;
d) development and justification of technical solutions directed at providing the reliability indexes specified in technical specifications and technical proposal;
e) product evaluation regarding manufacturability and correctness of inspection (testing, analysis and measuring) means choice;
f) product evaluation regarding standardization and unification parameters;
g) product evaluation regarding its compliance with ergonomics and technical aesthetics requirements.
h) variants checking for patent clearance and competitiveness, preparation of an application for invention;
i) variants checking for compliance with safety and industrial sanitation requirements;
j) comparative evaluation of the variants under consideration, issues related to metrological support of the product under development;
k) choice of product optimal variant (variants), choice justification, making of principal solutions; confirmation (or clarification) of product specified requirements (technical characteristics, quality indexes and others);
l) listing of works which should be performed at the following stage of designing in addition or for works clarification.
Example of E.1. The article “Refrigeration unit for storeroom compartments based on water-cooled condensing unit” may be considered as main data for drawing up the sketch design being executed with the aim of making principal solutions for production of refrigeration storeroom and condensing unit ККА-24-W and also as the data giving a general idea about the principle of operation and arrangement.
To become familiar with all design stages and examples of their performance, proceed to the review of the article “Stages of designing”.