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- Networks and Telecommunications: Design and Operation, Second Edition.
Martin P. Clark
Copyright © 1991, 1997 John Wiley & Sons Ltd
ISBNs: 0-471-97346-7 (Hardback); 0-470-84158-3 (Electronic)
42
Selecting and
Procuring Equipment
The preceding chapter described the factors in outline equipment design whichare crucial to the
success of the network evolution plan. Having a good plan is one thing; executing it is another,
andinthisrespecttheorderinganddelivery of theequipmentshouldreceiveconsiderable
attention. This is an activity often referred to as ‘procurement’, and it can be carried out very
successfullyhighly
by mechanistic management methods.
Various‘project
management’
techniques are available which tackle network design as if it were the input of a procurement
‘process’, much as ‘raw material’ is the input to a manufacturing ‘process’. In production-line
fashion, project management techniques lead the project through its design and checking stages,
and on to ordering, installation, and testing. However, in the same way as a poor raw material
has an effect right through to the end productof a manufacturing chain,so the defects of a poor
network design cannot be made good during implementation. This chapter describes a typical
methodology for selecting and procuring equipment, starting from the outline equipment design.
42.1 TENDERING FOR EQUIPMENT
Except for some of the largest corporations, very few companies that operatenetworks
also manufacture the equipment that goes to make them up; everything from personal
computer links upwards needs to be bought from other manufacturers. small pieces
For
of equipment like modems the purchase may be straightforward, because a range of
itemsmeetinga standard specification(say, an ITU-T V-series recommendation) is
available from a number of manufacturers. The purchaser then has timeto concentrate
on the finer differences (size, price, reliability, ease of maintenance, etc.) of the various
equipments, and to choose what suits them best. More costly equipment, like major
transmission systems or large exchanges, can seldom be bought ‘off-the-shelf. Instead,
the differing circumstance of each network and application means that a considerable
amount of ‘adaptive engineering’ is required in each case, to modify or upgrade the
manufacturer’sown ‘basic’ equipmentdesign.Selectingsuitableequipment is then
763
- 764 SELECTING AND PROCURING EQUIPMENT
much more difficult, because at the time of order it may be that none has yet been
developed. Under these circumstances, the normal method of equipment selection is by
an invitation to tender ( I T T ) ,request f o r proposal ( R F P ) or request f o r quotation ( R F Q )
and procurement follows after a contract has been placed with the manufacturer who
has tendered a price and a technical conformance nearest to the specification.
As well as a technical specification, an invitation to tender includes a number of
commercial and other contract conditions. The specification itself either lays out in
precise detail the individual electrical componentsand connections to be made, or it is a
functional specijication which lays out only which general functions must be performed
and which external interfaces are required. Functional speclJications are preferred by
tenderers and manufacturers alike because they place fewer constraints on the internal
design of the equipment. They permit a wider range of manufacturers to consider
adaptation oftheirproducts to meettheexternalinterfacerequirements. Forthe
purchaser, the larger the number of equipment manufacturers kept in competition and
providing ‘standard’ equipment, lower tendered
the the prices will be. For the
manufacturer the benefit is the larger market.
Each tender sets out the degree to which the equipment can be adapted to conform
with the specification, the degree to which the commercial conditions are considered
acceptable, and the quoted price. Even if none of the tenders meet the specifications and
commercial conditions in every respect, purchasers can at least gain an understanding
of each piece of equipment and decide on their owntrade-offs between various factors,
which are
e price and conditions for payment
m amount of further technical development required by an existing product, and how
much confidence there is that it can be achieved
e ease of equipment maintenance
e time required for installation, and whether the in-service date is early enough
m quality of product and installation
e modularity of kit; the ease of with which parts may be replaced or with which a
subsequent equipment extension may be carried out
m warranty and after-sales service
m the area and standard of accommodation required
m robustness and reliability of equipment
m political factors (nationality and financial liquidity of manufacturer, etc.)
m software licence and conditions
The process of invitation-to-tender and response is illustrated in Figure 42.1 and is
much the same, no matter what type of equipment is being purchased. The length of
each of the working documents (specification, tender, etc.) depends on the complexity
of therequirementandthe confidence gainedfromprevious
experience, the
but
contract itselfneedsonly to be ashortdocumentcommittingthemanufacturerto
- TENDERING FOR 765
Outline
network 'vision'
-
Detailed network
design
c
Equipment
specification and
preparation of the
invitation to tender
document
I
I
Manufacturers
tenders
I
I
E v a l u a t i o n of t e n d e r s ,
a n df u r t h e r n e g o t l a t t o n
l
P l a c e m e n t o f contract
with chosen manufacturer
I P r o j e c ti m p l e m e n t a t i o n
Figure 42.1 Procuring
equipment
conformwiththetenderresponse.Intheeventofafailure to conformwiththe
requirements of the contract, a number of penal clauses usually cover each of the
possible eventualities. For example, failure on the part of the manufacturer to develop a
given function may result in no payment, while failure on the part of the purchaser to
pay a given instalment, or to provide some detailed information on a given date may
nullify the contractual obligation placed on the supplier.
- 766 SELECTING AND PROCURING
EQUIPMENT
42.2 PROJECT MANAGEMENT
Even before the equipment goes out to tender, the job of project management must
have commenced, to coordinate all the separate aspects associated with the provision.
Equipment room accommodationwill be needed (someto a clinical standard) - built or
refurbished by a separatelycontractedcompany; power andstandby generator
equipment may need to be purchased and installed; and all sorts of changes in the
network may need to be undertaken.
During tendering,sound
a project management keeps task schedule,
each on
extracting prompt replies from manufacturers, insisting on rigorous evaluation and
timely contract placement. At the next stage the job becomes one of overseeing the
manufacturer’s work and quality, andof coordinating the supporting in-house other or
contractors’ activities.
Later on in the process, prior to the contract completion date (CCD), purchaser the
should test the equipment, especially any new developments, to check conformance
with the specification before final acceptance and payment.
The key to successful project management is early project planning. This must be
thorough and realistic. Forgetting some activities, programming too much or too little
or
time for other activities, can seriously upset thesmooth running of the entire project.
It is valuable during the project planning stage to undertake a critical path analysis.
Thissets out the relationship betweeneach of thesub-projects,laying out the full
sequence of events (or sub-projects) and the dependency of any individual event start
date on the completionof an earlier event. For example, it would not be possible to fit-
out a building before it had been built, but it might not matter whether the electrical
wiring or theplumbing were to be carriedout first.Thisconsecutivesequence of
interdependent sub-projects determines the earliest date at which the project could be
completed. If any of the sub-projects were to take longer than scheduled, then the
earliest possible project completiondate would slip by at least the same number of days.
Figure 42.2 illustrates a simple critical path analysis project schedule. A number of
computer software packages are available for this purpose (e.g. Microsoft Project).
The exchange installation project depicted in Figure 42.2 comprises ten sub-projects
or events. Four of these events make up the critical path of the project. These are the
building and fitting out of the accommodation, followed by the exchange installation,
the exchange testing, and the wiring-up of the network. None of these activities can
commence before the previous one has been completed, so that the consecutive time
period required for their completion determines the minimum overall project length.
Slippage in any of these four sub-projects delays the project’s earliest completion date
(i.e. the exchange opening).
In contrast, the other six events do not lie on the critical path. This means that a
degree of slack time is available. For example, a total of 29 months is available to
recruit and train maintenancestaff, but only 10 months are required. These tasks could
therefore be delayed for 19 months after the project start date without affecting the
project end date. In fact, the only constraint in this case is that the training of staff
cannot commence before January 1991, after the exchange installation, otherwise there
is no equipment to be trained on. This relationship is shown by the dotted line arrow on
Figure 42.2, indicating a dependent event. The use of a dotted line arrow indicates that
it is only a one-way dependency, rather than two-way. In other words, the exchange
- PROJECT MANAGEMENT 767
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- 768 SELECTING AND PROCURING
EQUIPMENT
must be installed before training can commence, but in our example it is not the case
that the maintenance staff need to have been recruited before exchange testing can
commence.
Other events which arenot time-critical are ordering circuits the
the of and
installation of transmission equipment. The ordering must precede the installation, but
the ten months needed for the work are far less than the 26 months available. The
transmission equipment installation cannot commence until July 1990 at the earliest,
after the accommodation has been prepared.
Not onlydoesacritical path analysisprovideachecklist of allthetasks to be
undertaken, itprovidesastraightforwardandmechanisticmethodformarshalling
resources and ensuring the timely completion of critical path events. Furthermore, it
allows the scheduling of non-critical events in the most efficient and convenient manner
possible within the timescale. For example, staff training in Figure 42.2 could start at
any time between January and February 1991, according to convenience.
42.3 PROCUREMENT POLICY
Before purchasing items of equipment, it is prudent for any company to determine a
properprocurement policy. A procurement policyprotects interests
the of the
purchaser.Itisnogoodalwaysbuyingthecheapestequipment if thismeansthe
eventual acquisition of a diverse range of slightly incompatible equipment, each piece
requiring different spares and differently trained maintenance staff, and with insoluble
compatibility problems should the equipments ever need to be integrated. On the other
hand, if a company alwayspurchases equipment a
from single supplier, then
dependency creeps the
in; supplier’sprices escalate
may to give a better profit
margin; worse still, the supplier may go out of business or become unreliable or un-
cooperative. Using even a range
small of differentsuppliers
helps to
maintain
competition between them. An example of a complete equipment purchasing policy
might be that ‘new equipment purchasedshould be compatible an
with IBM
equipment’.
At the time of tendering for equipment, due account should be taken of the company
procurement policy. It makes poorsense to write a specification which precludes all but
onesupplier, when the company procurement policy is topromote competitive
tendering,withalongtermobjective of maintaining at leasttwosuppliers.Over-
worded and complicated specifications
tend to havethe effect of precluding
suppliers, so that in general it is best to try to keep conditions of tender and contract
as simple as possible.
42.4 PLANNING DOCUMENTATION
Before commencing any major project, whether it involves procurement or not, the
network operator must determine the long term network strategy or ‘vision’ of which
theprojectformsa part.The strategyshouldset outthelong termobjectives for
network development, and against the backdrop of short term constraints, it should
- PLANNING DOCUMENTATION 769
map out a series of projects to achieve the long term goal. Typically, the strategic goal
may be reachedinanumber of different ways, and theanalysisleading up toa
recommendation of a particular plan should consider and reject a number of alternative
options.
Having laid out the long term strategy and mapped it into a series of component
projects,theplanning,coordination, anddocumentation of eachindividualproject
must commence. Any project is best documented in a controlled and layered structure
toensure easy reference to detailed information while retaining consistency and
oversight across the whole job.
Figure 42.3 shows a schematic documentation structure of three layers, oriented in a
triangular fashion. At the top or ‘strategy’ layer the documentation is light, laying out
the overall objectives, the end goal, the resources to be used, and in outline the major
component projects of the strategy. At the second or ‘plan’ layer a number of separate
planning documents exist, each comprehensively describing an individual project. The
plan needs to covereverything: service and project timescales, staff responsibilities,
networktopology,maintenanceprocedures,customer service arrangements,accom-
modation requirements, sales, procurement,customer billing, training and all other
conceivable aspects. Ideally, the document refers to the strategy that it supports, and
also explains the existence and inter-relationship of any more detailed specifications
which exist to support it. The third and layer of documents, ‘specifications’, covers
last
the detailed technical definitions and procedures.
Specification documents are the meat of the project. It is documents at this level of
detail that are tendered to prospective manufacturers and are subsequently used for
definitive reference. That is notto say that layer 1 and 2 documentsareany less
important, because they hold the entire project and strategy together.
Given a proper document structure, a document registration procedure should be set
up toensure proper quality inspection of documents. Documents should be checked for
Layer 1
Layer 2
Layer 3
Figure 42.3 A layered documentation structure
- 770 SELECTING AND PROCURING
EQUIPMENT
accuracy, comprehensiveness, and clarity by persons other than their original authors.
To ensure that there is no confusion over discrepancies between differently updated or
amendedversions of thesamedocument,a proper re-issuing andchange-control
procedure should be adopted.
42.5 THE TENDER DOCUMENT
The tender document orinvitation to tender describes the equipment to be supplied. It is
prepared by thenetwork-operator wheneveramajoritem of equipment is to be
procured. It describes which technical functions the equipment is expected to perform
and it includes any commercial conditions which apply to the supply contract. Once
prepared,thetenderdocument is sent tooneormore prospectivesuppliers,who
consider the requirements and send back formal replies, stating what they are able to
offer and the price to be charged if their offer is taken up.
Thetenderdocument the
and chosenmanufacturer’s response to it formthe
documentation of contract. Any subsequent contractual dispute between the network
operator and the supplier is resolved by reference to this documentation. From the
network operator’s point of view, it is important to ensure that the tender document
makes the obligations on any contracted supplier absolutely clear. The supplier on his
side aims to make it clear in the response, which of the specified items can be supplied
and which are not included in the offer. The most harmonious business relationships
and the most successful projects are based on accurate understanding. In the remainder
of the chapter we describe items that should to be included in the tender document.
42.5.1 CommercialConditions of Contract
In the opening section of the tender document a general introduction should be given,
explaining briefly the type of equipment required and in what timescales. This prevents
any‘no-hope’supplierfromwastingfurthertime by analysingallthedetail.The
commercial conditions of contract should go on explain in detail what items of work
to
are the obligation of the supplier, the timescales for delivery each item, and the terms
of
on which payment is to be made (for example, installments as each part is delivered, or
‘only when the whole job is done’). The commercial conditions also need to lay out the
penalties for failure to conformwiththerequirements of contract. Thesepenalties
sometimes include an obligation on the supplier to correct errors and may call for a sum
of money to be paid to the network operator as compensation for liquidated damage.
42.5.2 OtherGeneralConditions of Contract
The general conditions of contract may clarify any other legal or general constraints
which thenetworkoperatormight wish to impose. This sectionmightcoverthe
ownership of any document copyright, the ownership of patent rights and intellectual
- THE TENDER DOCUMENT 771
property rights (IPRs) of any new items that may be developed, and may cover general
conditions pertaining to the disclosure of information. The section may constrain the
supplier not to make press releases and should cover the procedure for resolution of
contract disputes. It could cover both parties’ rights to terminate the contract, and (if
relevant) the privilege of one party in the event of the other’s bankruptcy. Finally, the
section may clarify how particular legal constraints on one of the parties affects the
contract. For example, let us imagine that the network operator obliged by law not to
is
release information to aparticularthirdparty.Thisinformationmay,however, be
required by the supplier in order that the contract can be fulfilled. In such an instance
the supplier should be obliged by contract not to release the information to the third
party. This type of situation caneasily arise. Imagine a telephonecompany A buying an
exchange from company B, where company B is both a telephone network operating
companyandan exchangesupplier.Nowcompany A mayneed to reveal to its
exchange supplier details of its network configuration, and this may include details
pertinent to network business held jointly with one of company B’s network operating
competitors.Inthisinstancecompany A needs to release detailstotheexchange
supplier part of company B, but with the proviso that this information is not passed
backtocompany B’s networkadministrators,whomightgainunfaircompetitive
advantage from it.
42.5.3 Technical
Conditions
The technical part of the specification sets out the type of equipment required and its
detailedfunctions.Onceuponatime,manyofthelarge publictelecommunications
operators (PTOs) had a hand in designing the equipment. In those days the specifica-
tion was at a level of detail of an actual equipment design, almost a detailed circuit and
componentdesign, so thatcontracts were principallyformanufacture.Nowadays,
however, it is more common for purchasers (including PTOs) to provide a functional
speczjication, laying out no more than the broad functions the equipment expected to
is
perform, together with the details of any external interfaces enabling thenew device to
interwork correctly with other network components. As we have already noted, the use
of a functional specification as opposed to an equipment design speclJication promotes
competition among prospective suppliers, with a long term benefit of lower costs and
higher quality. Items which may be pertinent in the specification are explained below
0 accommodationandenvironment
0 networkconfigurationandtopology
0 operationandmaintenance
0 equipment size andperformance
0 functions
0 control interfaces
0 power
supply
- 772 SELECTING AND PROCURING EQUIPMENT
Figure 42.4 A modern ISDN exchange (Courtesy of Siemens A G )
The accommodation and environment in which the equipment is to be installed: any
constraining floor layouts, temperature considerations or other adverse conditions (e.g.
siting of equipment in a manhole). -*
The network configuration and topology in which the equipment is to work, include
the specification of any interfaces to other network components.
The operation and maintenance requirements: whether remote control or monitoring
of equipment is required; which test points and test equipment is required; whether
internal diagnostic programmes are required; what failure alarms are required.
The equipment size and expected performance; for an exchange, the total daily traffic
throughput in calls, and the peak hour traffic intensity (number of simultaneous calls)
should quoted,
be together with performance expectations underoverload.
The
number of busy hour call attempts (BHCA for circuit switched networks) or packets
(packet switched) may be important to the dimensioning of the exchange processing
capacity, and the total number of daily call attempts may govern how much storage
capacity is required for any statistical information which may be required from the
exchange. For a transmission system, the bandwidth of the system or the bit rate needs
to be quoted, along with its jitter performance, sensitivity to noise, and other relevant
information.
- THE TENDER DOCUMENT 773
The functions of theequipment. For an exchangethisincludes defining the call
control, call routingcapabilities and services thatare required,together with the
method of switching, the method of changing routing data held in the exchange, and
the signalling systems to be provided. In addition, recorded announcements may be
required, along with particular methods or formats for output traffic recording, call
of
charging and accounting information. Transmission equipment may need to provide
maintenance staff with means
some of remotemonitoring failures, and of
reconfiguring equipment.An automatic switchover to an alternative line system
may be required.
The control interfaces. It is increasingly common for network operators to expect to
be able to control, monitor and reconfigure the equipment within their network from a
single computerized‘control centre’. Anyequipmentdestinedfor such a network
requires the necessary computer interfaces to be built in. These must be covered by the
specification. Conversely,theequipmentsuppliedmay be controllingother devices,
and so it too must conform to a defined control interface. (An exchange, for example,
mayhave to control externalechosuppressors or circuitmultiplicationequipment,
and a computer may be required to monitor and control any of awholerange of
devices.)
The type of power supply. The supplier may need to provide equipment for working
at a given voltage. Alternatively, the power equipment (including batteries and back-up
generators)may need to be provided by thesupplier.Oftenelectronicequipment
demands uninterruptable power supply ( U P S ) , because computer data canbe lost as the
result of instantaneous breaks in power.
42.5.4 Reliability
Conditions
Reliability expectations should be quoted as a series of measurable parameters, quoted
with reasonable target values. Measures such as ‘the number of separate instances of
failure, measured month on month, shall not exceed. . . ’ are much better than more
vague parameters like ‘the mean time between failures ( M T B F ) shall be greater than
three years’, even if MTBF is an oft-quoted parameter. The problem with the latter
statistic (MTBF) is that the long measurement period that is involved makes it virtually
unenforceable. (If two failures happen in the first six months, does this mean that the
next failure will nothappenforat least five-and-a-half years?) Obligations of the
supplier on failing to meet the reliability conditions should also be laid out. For systems
like publictelephoneexchanges or high grade computer control systems, where no
break in service is acceptable to customers, availability values as high as (or even better
than) 99.9% are common, though even more stringent measures may be appropriate.
(It is sometimes not hard to meet a 99.9% availability for a network as a whole, even if
some individual ports are outof service for days orweeks at a time, because the overall
incidence of failure is nowadays usually very low.) Other considerations of reliability
are the conditions and prices for the supply of spares and for after-sales support, ideally
lasting for the lifetime of the equipment. The network operator does not want to be left
in the position, a short time after equipment purchase, where the supplier changes the
product range, and stops producing spares for the now obsolescent equipment.
- 774 SELECTING AND PROCURING EQUIPMENT
42.5.5 ProjectManagementConditions
The tender document should lay out any special procedures for project management.
The purchaser, for instance may make conditions on the work practices of the supplier,
constraining noise, mess, access to site or health and safety. In addition it may be
necessary to clarify responsibilities: whether for instance the supplier or the purchaser
is
to wire-up the equipment on site. Particular installation work practices may need to be
adopted. Also, for a large and lengthy project, the purchaser may wish the supplier to
build check points into the development and installation, so that the rate of progress
through the project can be fairly closely monitored.
42.5.6 Quality
Assurance
The tender document should set down the particular measures that will be applied by
the purchaser during acceptance testing to determine whether the equipment is fit-for-
purpose. Usually a fair proportion of the monies are withheld until these tests have
been completed. The tender document may also mandate the supplier to carry out
internalinspections at variousstages of development andmanufacture,and may
demand adherence to a quality work practice methodology such as those laid out the
in
I S 0 9000-series standards.
42.5.7 Documentation Training
and
In some cases, particularly when an open tender is undertaken between a number of
competing suppliers, the purchaser may choose a type of equipment that is new to the
network. this the
In case purchaser requires
training the
for maintenance and
administration staff, and full documentation for later reference. This should be stated in
the tender document, so that the price for it receives full consideration. Alternatively, it
could be the subject of a separate contract.
42.5.8 Definitions
Finally, it is usual to include a glossary of definitions within the tender document, as a
ready reference for terms of jargon or unfamiliar abbreviations. This is merely good
documentation practice. The following list illustrates the parts of a complete tender
document, butof course the size of it and the omission of any irrelevant parts arepurely
at the purchaser’s discretion.
0 Commercial
conditions
0 Other general conditions
0 Technical
conditions
0 Reliability
conditions
- SUMMARY 775
0 Projectmanagementconditions
0 Quality
assurance
0 Documentationandtraining
0 Definitionsandglossary
42.6 SUMMARY
In summary, the procurement of equipment can be a relatively straightforward and
mechanistic process provided that the necessary planning is undertaken at an early date,
and provided that care taken in preparing the documentation. The commonest causes
is
of project failure stem from faults in the
very early stages. The cost of rectification can
be enormous.
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